Sample records for nerve root displacement

  1. Immunohistochemistry of displaced sensory neurons in the trigeminal nerve root.

    PubMed

    Marinkovi?, Slobodan; Cetkovi?, Mila; Gibo, Hirohiko; Todorovi?, Vera; Janci?, Jasna; Milisavljevi?, Milan

    2010-01-01

    The aim of this study was to examine the morphology and the immunohistochemical features of displaced ganglion cells in the trigeminal nerve root (TNR). Forty human TNRs of 20 persons, obtained during routine autopsy in accordance with the Declaration of Helsinki, were examined following Klüver-Barrera and azan trichrome histological staining, and immunohistochemical reactions against certain neuronal markers, neuropeptides and neurotransmitters. A total number of 61 displaced neurons were investigated, which were present in 80% of individuals studied. Displaced neurons were found in 55.0% of the TNRs, either in the sensory portion (22.5%), motor portion (22.5%) or both (10.0%). Neuronal diameter varied from 12.5 x 25.0 to 45.0 x 63.7 (mean 27.6 x 41.6) microm, and in area between 245 and 2,065 (mean 927) microm(2). Each neuron was surrounded by 2-17 elongated satellite cells per slice. The immune reaction was positive in all the neurons studied for neuron-specific enolase, protein gene product 9.5, neurofilament protein and synaptophysin, and in some neurons for calcitonin gene-related peptide (CGRP; 24.4%), cholecystokinin (CCK; 13.3%), somatostatin (SST; 17.8%), substance P (SP; 15.6%), vasoactive intestinal polypeptide (4.4%), neuropeptide Y (8.9%), and serotonin (11.1%). The immune reactions were most frequent against the CGRP, SP, CCK and SST. We concluded that displaced neurons in the TNR morphologically and immunohistochemically resembled the sensory neurons in the trigeminal ganglion. PMID:19923783

  2. Nerve and Nerve Root Biomechanics

    Microsoft Academic Search

    Kristen J. Nicholson; Beth A. Winkelstein

    \\u000a Together, the relationship between the mechanical response of neural tissues and the related mechanisms of injury provide\\u000a a foundation for defining relevant thresholds for injury. The nerves and nerve roots are biologic structures with specific\\u000a and important functions, and whose response to mechanical loading can have immediate, long-lasting and widespread consequences.\\u000a In particular, when nerves or nerve roots are mechanically

  3. Vascular permeability of spinal nerve roots

    Microsoft Academic Search

    C. Å. V. Pettersson; H. S. Sharma; Y. Olsson

    1990-01-01

    The permeability of blood vessels in rat spinal nerve roots was investigated with Evans blue-albumin as an in vivo macromolecular tracer and lanthanum as tracers as an electron microscopic ionic marker added to a fixative. Rats injected intravenously with Evans blue, showed macroscopic distinct staining of dorsal root ganglia, whereas spinal nerve roots remained unstained. Fluorescence microscopy, however, revealed clear

  4. Massive nerve root enlargement in chronic inflammatory demyelinating polyneuropathy

    Microsoft Academic Search

    W Schady; P J Goulding; B R Lecky; R H King; C M Smith

    1996-01-01

    OBJECTIVE: To report three patients with chronic inflammatory demyelinating polyneuropathy (CIDP) presenting with symptoms suggestive of cervical (one patient) and lumbar root disease. METHODS: Nerve conduction studies, EMG, and nerve biopsy were carried out, having found the nerve roots to be very enlarged on MRI, CT myelography, and at surgery. RESULTS: Clinically, peripheral nerve thickening was slight or absent. Subsequently

  5. Spinal Cord and Nerve Root Decompression

    Microsoft Academic Search

    Keith R. Lodhia; Paul Park; Gregory P. Graziano

    Tumors of the vertebral column include both primary and metastatic lesions. These tumors can cause significant morbidity consisting\\u000a of lesional pain and pain from deformity. Compression of the spinal cord and spinal nerve roots can also cause radicular pain\\u000a as well as neurologial deterioration including sensory deficits, weakness, paralysis, and\\/or sexual\\/bowel\\/ bladder dysfunction.\\u000a In cases of metastatic lesions, the spine

  6. Somatosensory evoked potential from S1 nerve root stimulation

    Microsoft Academic Search

    Xiao-Dong Wu; Yu Zhu; Wen-Jun Chen; Xiang Jin; Nicholas Tsai; Huang-Yuan Huang; Jian-Yuan Jiang; Dong-Qing Zhu; Pei-Ying Li; Robert Weber; Wen Yuan; Hua-Jiang Chen

    The objective of this study was to detect cerebral potentials elicited by proximal stimulation of the first sacral (S1) nerve\\u000a root at the S1 dorsal foramen and to investigate latency and amplitude of the first cerebral potential. Tibial nerve SEP and\\u000a S1 nerve root SEP were obtained from 20 healthy subjects and 5 patients with unilateral sciatic nerve or tibial

  7. Reconstruction of nerve root sheaths for sacral extradural spinal meningeal cysts with spinal nerve root fibers.

    PubMed

    Sun, Jianjun; Wang, Zhenyu; Li, Zhendong; Wu, Haibo; Yen, Ruyu; Zheng, Mei; Chang, Qing; Liu, Isabelle Yisha

    2013-11-01

    This study analyzed the clinical characteristics and outcomes of sacral extradural spinal meningeal cysts with spinal nerve root fibers treated by reconstruction of the nerve root sheaths. The relationships between the cysts and spinal nerve root fibers were examined microscopically, the cysts were partially excised, and the defects were oversewn to reconstruct the nerve root sheaths. The Improved Japanese Orthopedic Association (IJOA) scoring system was used to evaluate preoperative and postoperative neurological function. Thirty-eight patients were included in this study, with a mean age of 41.4 ± 15.57 years. The mean IJOA score was 18.8 ± 1.32 preoperatively and 19.6 ± 0.65 postoperatively, which was a significant difference (t=-3.77, P=0.001). These results indicate a significant improvement in neurological function after surgery. The most significant improvement in neurological function was sensation (z=-2.86, P=0.004), followed by bowel/bladder function (z=-2.31, P=0.02). PMID:24008383

  8. Proposed Classification of Auriculotemporal Nerve, Based on the Root System

    PubMed Central

    Komarnitki, Iulian; Tomczyk, Jacek; Ciszek, Bogdan; Zalewska, Marta

    2015-01-01

    The topography of the auriculotemporal nerve (ATN) root system is the main criterion of this nerve classification. Previous publications indicate that ATN may have between one and five roots. Most common is a one- or two-root variant of the nerve structure. The problem of many publications is the inconsistency of nomenclature which concerns the terms “roots”, “connecting branches”, or “branches” that are used to identify the same structures. This study was performed on 80 specimens (40 adults and 40 fetuses) to propose a classification based on: (i) the number of roots, (ii) way of root division, and (iii) configuration of interradicular fibers that form the ATN trunk. This new classification is a remedy for inconsistency of nomenclature of ATN in the infratemporal fossa. This classification system has proven beneficial when organizing all ATN variants described in previous studies and could become a helpful tool for surgeons and dentists. Examination of ATN from the infratemporal fossa of fetuses (the youngest was at 18 weeks gestational age) showed that, at that stage, the nerve is fully developed. PMID:25856464

  9. Anatomical feasibility of transferring the obturator and genitofemoral nerves to repair lumbosacral plexus nerve root avulsion injuries.

    PubMed

    Gang, Yin; Wang, Tienan; Sheng, Jun; Hou, Chunlin; Lin, Haodong

    2014-07-01

    Nerve transfer is a valid surgical procedure for restoring lower-extremity function after lumbosacral plexus nerve root avulsion. We determined the anatomical feasibility of transferring the obturator and genitofemoral nerves for this purpose. The obturator, genitofemoral and femoral nerves, and the S1 and S2 nerve roots on both sides were exposed in 10 cadaver specimens. We traced all nerves to their origins. The lengths of the obturator and genitofemoral nerves were measured from their origins to their exits from the abdominal cavity. The transverse and longitudinal diameters of all nerves were measured. Specimens were obtained to determine the total number of myelinated fibers in each nerve. The proximal part of the left obturator nerve was anastomosed with the distal part of the right femoral nerve, between the vertebrae and the peritoneum, with an overlap of 2-3 cm. Similarly, the proximal parts of the right obturator and genitofemoral nerves were anastomosed with the ipsilateral S1 and S2 nerve roots, respectively, with an overlap of 2-4 cm. The obturator nerve contained approximately one-third of the number of fibers (4,300-7,800) presenting in the femoral nerve (13,500-21,000). Similarly, the number of fibers found in the S1 nerve root was in the range 5,200-8,900. The genitofemoral nerve contained approximately half the number of fibers (3,000-4,500) presenting in the S2 nerve root (4,600-8,400). The obturator and genitofemoral nerves could be suitable donor nerves for repairing lumbosacral plexus nerve root avulsion. PMID:24288352

  10. Extradural Corticosteroid Injection in Management of Lumbar Nerve Root Compression

    PubMed Central

    Dilke, T. F. W.; Burry, H. C.; Grahame, R.

    1973-01-01

    The effect of extradural corticosteroid injection in patients with nerve root compression syndromes associated with degenerative disease of the lumbar intervertebral discs was assessed in a double-blind controlled trial on 100 consecutive inpatients assigned by random allocation to treatment and control groups. Assessment during admission and at three months revealed statistically highly significant differences in respect of relief of pain and resumption of normal occupation in favour of the group treated by extradural injection. This treatment seems to be a valuable adjunct to the management of lumbar nerve root compression syndromes associated with degenerative disc disease. PMID:4577015

  11. Eight nerve, root nucleus Dolores E. Lpez

    E-print Network

    Oliver, Douglas L.

    Reticulospinal bundle Trapezoid body Pn Dorsal acoustic stria #12;Labeled PnC reticulospinal neurons (in brown- cochlear nucleus response) Kainic acid lesion in the VIII nerve abolish the startle Mean startle amplitude elicited by three different noise burst intensities before and after bilateral Kainic acid lesioning

  12. Hypertrophic nerve roots in a case of Roussy-Lévy syndrome.

    PubMed

    Haubrich, C; Krings, T; Senderek, J; Züchner, S; Schröder, J M; Noth, J; Töpper, R

    2002-11-01

    Hypertrophic radiculopathy is a rare feature of neuropathies. Single cases of enlarged nerve roots have been described in hereditary motor sensory neuropathies (HMSN) and chronic inflammatory demyelinating diseases (CIDP). This is the first description of hypertrophied nerve roots in a patient with Roussy-Lévy syndrome. MRI did not show contrast enhancement of the enlarged nerve roots or nodular lesions. PMID:12428130

  13. Characterization of a chondroitin sulfate hydrogel for nerve root regeneration

    NASA Astrophysics Data System (ADS)

    Conovaloff, Aaron; Panitch, Alyssa

    2011-10-01

    Brachial plexus injury is a serious medical problem that affects many patients annually, with most cases involving damage to the nerve roots. Therefore, a chondroitin sulfate hydrogel was designed to both serve as a scaffold for regenerating root neurons and deliver neurotrophic signals. Capillary electrophoresis showed that chondroitin sulfate has a dissociation constant in the micromolar range with several common neurotrophins, and this was determined to be approximately tenfold stronger than with heparin. It was also revealed that nerve growth factor exhibits a slightly stronger affinity for hyaluronic acid than for chondroitin sulfate. However, E8 chick dorsal root ganglia cultured in the presence of nerve growth factor revealed that ganglia cultured in chondroitin sulfate scaffolds showed more robust growth than those cultured in control gels of hyaluronic acid. It is hypothesized that, despite the stronger affinity of nerve growth factor for hyaluronic acid, chondroitin sulfate serves as a better scaffold for neurite outgrowth, possibly due to inhibition of growth by hyaluronic acid chains.

  14. Altered Median Nerve Deformation and Transverse Displacement during Wrist Movement in Patients with Carpal Tunnel Syndrome

    PubMed Central

    Wang, Yuexiang; Filius, Anika; Zhao, Chunfeng; Passe, Sandra M.; Thoreson, Andrew R.; An, Kai-Nan; Amadio, Peter C.

    2014-01-01

    Rationale and Objectives: Carpal tunnel syndrome (CTS) is the most common peripheral nerve entrapment syndrome. Strong pinch or grip with wrist flexion has been considered a risk factor for CTS. Studying median nerve displacement during wrist movements may provide useful information about median nerve kinematic changes in CTS patients. The purpose of this study was to evaluate the deformability and mobility of the median nerve in CTS patients compared to healthy subjects. Materials and Methods: Dynamic ultrasound images were obtained in 20 affected wrists of 13 patients with CTS. Results were compared to complementary data obtained from both wrists of 10 healthy subjects reported in a previous study. Initial and final median nerve shape and position were measured and analyzed for six defined wrist movements. The deformation ratios for each movement were defined as the median nerve area, perimeter and circularity of the final position normalized by respective values assessed in the initial position. The median nerve displacement vector and magnitude were also calculated. Results: The deformation ratio for circularity was significant less in CTS patients compared to healthy subjects during wrist flexion (P<0.05). The mean vector of median nerve displacement during wrist flexion was significantly different between CTS patients and healthy subjects (P<0.05). The displacement magnitude of the median nerve was found to be less in CTS patients compared to healthy subjects during most movements, with the exception of wrist extension with fingers extended. Conclusions: CTS Patients differ from normal subjects with regard to mobility and deformability of the median nerve. PMID:24594417

  15. Comparison of neuropathic pain and neuronal apoptosis following nerve root or spinal nerve compression

    PubMed Central

    Sekiguchi, Yasufumi; Konno, Shin-ichi; Kobayashi, Hideo; Homma, Yoshimi; Kikuchi, Shin-ichi

    2009-01-01

    Altered dorsal root ganglion (DRG) function is associated with neuropathic pain following spinal nerve injury. However, compression of the cauda equina and dorsal rhizotomy proximal to the DRG do not induce significant pain, whereas in the spinal nerve and peripheral nerve, injury distal to the DRG does induce neuropathic pain. Caspase signaling induces apoptosis, and caspase inhibitors prevent pain-related behavior. The degree of DRG neuronal apoptosis is thought to play a role in pain behavior. We suggest that differences in pain behavior according to the injury sites within the DRG may be related to imbalances in apoptotic injuries. The aim of this study was to determine which compression injury was more painful and to compare behavior with expression of tumor necrosis factor (TNF)-alpha in DRG and apoptosis in the DRG following crush injury to the L5 nerve root or L5 spinal nerve. Sprague–Dawley rats received a crush injury to the L5 spinal nerve (distal to the DRG), crush injury to the L5 nerve root (proximal to the DRG), or no crush injury (sham). Mechanical allodynia was determined by the von Frey test. Expression of TNF-alpha was compared among three groups using immunoblot findings. Furthermore, we compared the percentage of neurons injured in the DRG using immunostaining for apoptotic cells and localization of activated caspase 3. Mechanical allodynia was observed in both crush injury groups. The duration of mechanical allodynia in the distal crush group was significantly longer than in the proximal crush group (P < 0.05). TNF-alpha expression was increased in DRG neurons following injury. DRG apoptosis in the distal crush group was significantly higher than in the proximal group at each time point (P < 0.05). This study suggests that spinal nerve crush injuries produce a greater degree of DRG apoptosis than do corresponding nerve root crush injuries, and that the former injuries are associated with longer lasting mechanical allodynia. Thus, differences in the time course of mechanical allodynia might be associated with an imbalance in DRG apoptosis. PMID:19543754

  16. Pathologic Anatomy and Mechanisms of Nerve Root Compression

    Microsoft Academic Search

    Jan T. Wilmink

    \\u000a In 1934, Mixter and Barr reported nineteen cases of rupture of the intervertebral disc with the involvement of the spinal\\u000a canal, and so ushered in the “dynasty of the disc”. Their paper described compression of the spinal cord, cauda equina or\\u000a exiting nerve root by the her-niated material, and included four cases with a cervical localisation, four cases in the

  17. Intradural nerve root hematoma in the lumbar spine. A case report

    Microsoft Academic Search

    M. Taghipour; S. Javadi; Y. Attaran; M. H. Bagheri

    2008-01-01

    Intradural nerve root hematoma of the lumbar spine is extremely rare and can cause compression of the cauda equina. This case,\\u000a which presented with low back pain and radiation to both lower extremities, diagnosed as an intradural hematoma of nerve root\\u000a by magnetic resonance imaging (MRI) and was totally removed successfully. Intradural nerve root hematoma can present with\\u000a or without

  18. Ultrasonographic reference sizes of the median and ulnar nerves and the cervical nerve roots in healthy Japanese adults.

    PubMed

    Sugimoto, Takamichi; Ochi, Kazuhide; Hosomi, Naohisa; Mukai, Tomoya; Ueno, Hiroki; Takahashi, Tetsuya; Ohtsuki, Toshiho; Kohriyama, Tatsuo; Matsumoto, Masayasu

    2013-09-01

    The objective of this study was to identify, for practical use, ultrasonographic reference values for nerve sizes at multiple sites, including entrapment and non-entrapment sites along the median and ulnar nerves and among the cervical nerve roots. We verified reliable sites and site-based differences between the reference values. In addition, we found associations between the reference nerve sizes and several physical characteristics (gender, dominant hand, age, height, weight, body mass index [BMI] and wrist circumference). Nerves were measured bilaterally at 26 sites or levels in 60 healthy Japanese adults (29 males; age, 35.4 ± 9.7 y; BMI, 22.3 ± 3.6 kg/m(2); wrist circumference, 16.0 ± 1.3 cm on the right side and 15.9 ± 1.2 cm on the left side). The mean reference nerve sizes were 5.6-9.1 mm(2) along the median nerve, 4.1-6.7 mm(2) along the ulnar nerve and 2.14-3.39 mm among the cervical nerve roots. Multifactorial regression analyses revealed that the physical characteristics most strongly associated with nerve size were age, BMI and wrist circumference at the entrapment sites (F = 7.6, p < 0.01, at the pisiform bone level of the carpal tunnel; F = 15.1, p < 0.001, at the level of Guyon's canal), as well as wrist circumference and gender at the non-entrapment sites (F = 70.6, p < 0.001, along the median nerve; F = 24.7, p < 0.001, along the ulnar nerve). Our results suggest that the factors with the greatest influence on nerve size differed between entrapment and non-entrapment sites. Site-based differences in nerve size were determined using one-way analyses of variance (p < 0.001). Intra- and inter-observer reliability was highest for the median nerve, at both the distal wrist crease and mid-humerus; at the arterial split along the ulnar nerve; and at the fifth cervical nerve root level. No systematic error was indicated by Bland-Altman analysis; the coefficients of variation were 5.5%-9.2% for intra-observer reliability and 7.1%-8.7% for inter-observer reliability. PMID:23830101

  19. Pediatric primitive intraneural synovial sarcoma of L-5 nerve root.

    PubMed

    Peia, Francesco; Gessi, Marco; Collini, Paola; Ferrari, Andrea; Erbetta, Alessandra; Valentini, Laura G

    2013-04-01

    Primitive intraneural synovial sarcomas are rare in children. The authors report the case of a 7-year-old girl affected by intraneural synovial sarcoma of a lumbar nerve root, the first such lesion in this location described in a child. The lesion mimicked a schwannoma clinically and radiologically. There was long-lasting leg pain in a radicular distribution, and a well-demarcated intraneural tumor was seen on MRI. On this basis, the first resection was conservative. However, histological examination documented a classic biphasic synovial sarcoma, which was confirmed by immunohistochemistry. After radical resection and adjuvant treatment, complete disease control was achieved and verified at 5-year follow-up. This case strongly suggests that early diagnosis and a multidisciplinary approach to this unusual spinal lesion are essential to achieving a better prognosis. PMID:23414131

  20. Prolonged electrical stimulation causes no damage to sacral nerve roots in rabbits

    PubMed Central

    Yan, Peng; Yang, Xiaohong; Yang, Xiaoyu; Zheng, Weidong; Tan, Yunbing

    2014-01-01

    Previous studies have shown that, anode block electrical stimulation of the sacral nerve root can produce physiological urination and reconstruct urinary bladder function in rabbits. However, whether long-term anode block electrical stimulation causes damage to the sacral nerve root remains unclear, and needs further investigation. In this study, a complete spinal cord injury model was established in New Zealand white rabbits through T9–10 segment transection. Rabbits were given continuous electrical stimulation for a short period and then chronic stimulation for a longer period. Results showed that compared with normal rabbits, the structure of nerve cells in the anterior sacral nerve roots was unchanged in spinal cord injury rabbits after electrical stimulation. There was no significant difference in the expression of apoptosis-related proteins such as Bax, Caspase-3, and Bcl-2. Experimental findings indicate that neurons in the rabbit sacral nerve roots tolerate electrical stimulation, even after long-term anode block electrical stimulation. PMID:25206785

  1. Detection of cervical nerve root hypertrophy by ultrasonography in chronic inflammatory demyelinating polyradiculoneuropathy.

    PubMed

    Matsuoka, Naoki; Kohriyama, Tatsuo; Ochi, Kazuhide; Nishitani, Michie; Sueda, Yoshimasa; Mimori, Yasuyo; Nakamura, Shigenobu; Matsumoto, Masayasu

    2004-04-15

    Several studies have demonstrated abnormal MRI findings in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), especially hypertrophy and abnormal enhancement of spinal nerve roots, but there have been few reports on ultrasonographic findings of spinal nerve roots in CIDP. To determine whether ultrasonography (US) enables detection of hypertrophy of the cervical nerve roots, how frequently hypertrophy occurs in CIDP, and whether US findings correlate with any clinical and laboratory features, US of cervical nerve roots was performed using a 7.5-MHz linear-array transducer in 13 CIDP patients and 35 control subjects. A coronal oblique plane with a transducer placed on the lateral side of the neck was used to visualize the cervical nerve roots just after their point of exit from the cervical foramina, and their diameters were measured. US demonstrated hypertrophy of the cervical nerve roots in 9 (69%) of the 13 CIDP patients as compared with findings in control subjects. The degree of hypertrophy was significantly associated with the level of CSF protein (chi2=5.8, p<0.05, logistic simple regression analysis) but not with other clinical features. US is considered to be a useful method for evaluating cervical nerve root hypertrophy, which is frequently seen in patients with CIDP, particularly in patients with elevated level of CSF protein. PMID:15050432

  2. [Chronic inflammatory demyelinating polyradiculoneuropathy with hypertrophy of spinal roots, brachial plexus and cranial nerves].

    PubMed

    Aïdi, S; El Alaoui Faris, M; Amarti, A; Belaïdi, H; Jiddane, M; Guezzaz, M; Medjel, A; Chkili, T

    2002-09-01

    We report two patients who presented an atypical chronic inflammatory demyelinating polyradiculoneuropathy with massive nerve root and brachial plexus hypertrophy, and pseudotumoral supraclavicular mass. They also presented an hypertrophy of oculomotor and trigeminal nerves causing an exophthalmos and ocular palsy. Spinal root enlargement and cranial nerve hypertrophy was demonstrated by CT scanner and MRI. Brachial plexus biopsy showed a similar aspect of sural nerve, with an extensive onion bulb formation and perivascular inflammatory cell infiltration. There was an excellent response to steroids in both patients. PMID:12386527

  3. Primary glioblastoma of the trigeminal nerve root entry zone: case report.

    PubMed

    Breshears, Jonathan D; Ivan, Michael E; Cotter, Jennifer A; Bollen, Andrew W; Theodosopoulos, Phillip V; Berger, Mitchel S

    2015-01-01

    Gliomas of the cranial nerve root entry zone are rare clinical entities. There have been 11 reported cases in the literature, including only 2 glioblastomas. The authors report the case of a 67-year-old man who presented with isolated facial numbness and was found to have a glioblastoma involving the trigeminal nerve root entry zone. After biopsy the patient completed treatment with conformal radiation and concomitant temozolomide, and at 23 weeks after surgery he demonstrated symptom progression despite the treatment described. This is the first reported case of a glioblastoma of the trigeminal nerve root entry zone. PMID:25380115

  4. Ultrasonographic cross-sectional area of spinal nerve roots in cervical radiculopathy: a pilot study.

    PubMed

    Kim, Eunkuk; Yoon, Joon-Shik; Kang, Hyo Jung

    2015-02-01

    Recently, sonographic assessment has been considered an alternative method for evaluating cervical root lesions. The aim of this pilot study was to measure cross-sectional areas (CSAs) of cervical spinal nerve roots using high-resolution ultrasonography in patients with cervical radiculopathy, to compare the CSA of nerve roots between the affected and unaffected sides. Patients with a clinical diagnosis of unilateral cervical radiculopathy, who were referred to the Department of Physical Medicine and Rehabilitation in the University General Hospital by general practitioners, were prospectively recruited. The selected nerve roots were sonographically imaged at the most proximal location possible, where they exited over the transverse processor, just distal to that point. The CSA was measured three times using the trace tool available on the ultrasonography device. The CSA of each contralateral nerve root served as a control. Twenty-four patients (9 women; mean age, 53.7 yrs) were enrolled in this study. The CSAs were measured by ultrasonography in 5 pairs of C5 roots, 12 pairs of C6 roots, and 7 pairs of C7 roots. The mean CSAs of the affected and unaffected sides were 9.74 ± 1.95 and 9.47 ± 1.95 mm, respectively (P = 0.019). Spearman rank-order correlation test showed a positive relationship between the CSA of the affected nerve root and the duration of symptoms (?22 = 0.467, P = 0.021).This is, to the authors' knowledge, the first comparative study to obtain the CSA of spinal nerve roots in cervical radiculopathy. Increased CSA of the affected nerve root relative to the unaffected side, as demonstrated by ultrasonography, may be useful as an additive clue for the diagnosis of cervical radiculopathy. PMID:25415392

  5. The Relation Between Rotation Deformity and Nerve Root Stress in Lumbar Scoliosis

    NASA Astrophysics Data System (ADS)

    Kim, Ho-Joong; Lee, Hwan-Mo; Moon, Seong-Hwan; Chun, Heoung-Jae; Kang, Kyoung-Tak

    Even though several finite element models of lumbar spine were introduced, there has been no model including the neural structure. Therefore, the authors made the novel lumbar spine finite element model including neural structure. Using this model, we investigated the relation between the deformity pattern and nerve root stress. Two lumbar models with different types of curve pattern (lateral bending and lateral bending with rotation curve) were made. In the model of lateral bending curves without rotation, the principal compressive nerve root stress on the concave side was greater than the principal tensile stress on the convex side at the apex vertebra. Contrarily, in the lateral bending curve with rotational deformity, the nerve stress on the convex side was higher than that on the concave side. Therefore, this study elicit that deformity pattern could have significantly influence on the nerve root stress in the lumbar spine.

  6. Neurophysiological changes in spinal nerve roots subjected to tensile loading at several strain rates

    Microsoft Academic Search

    Gurjiwan Singh Virk

    2012-01-01

    \\u000aSpinal nerve roots have been implicated in many types of traumatic injuries such as motor vehicle accidents, falls, and sports injury, causing damage to brachial plexus and lumbosacral plexus. They have also been involved in lower back pain, disc herniation or protrusions, sciatica, and traumatic birth delivers such as shoulder dystocia. These roots undergo tension, resulting in traumatic axonal injury

  7. Anterograde transport of opioid receptors in rat vagus nerves and dorsal roots of spinal nerves: pharmacology and sensitivity to sodium and guanine nucleotides

    Microsoft Academic Search

    M. A. Zarbin; J. K. Wamsley; M. J. Kuhar

    1990-01-01

    We have utilized the technique of in vitro autoradiography to ascertain that opioid receptors are transported in the rat vagus nerve and in the rat dorsal spinal root fibers. In the dorsal roots, opioid receptors accumulated on both sides of the ligatures. In the vagus nerve, a distal accumulation of binding sites was difficult to detect, however, proximal to the

  8. Transverse Ultrasound Assessment of Median Nerve Deformation and Displacement in the Human Carpal Tunnel during Wrist Movements

    PubMed Central

    Wang, Yuexiang; Zhao, Chunfeng; Passe, Sandra M.; Filius, Anika; Thoreson, Andrew R.; An, Kai-Nan; Amadio, Peter C.

    2013-01-01

    The symptoms of carpal tunnel syndrome, a compression neuropathy of the median nerve at the wrist, are aggravated by wrist motion, but the effect of these motions on median nerve motion are unknown. In order to better understand the biomechanics of the abnormal nerve, it is first necessary to understand normal nerve movement. The purpose of this study was to evaluate the deformation and displacement of the normal median nerve at the proximal carpal tunnel level on transverse ultrasound images during different wrist movements, in order to have a baseline for comparison with abnormal movements. Dynamic ultrasound images were obtained in both wrists of 10 asymptomatic volunteers during wrist maximal flexion, extension and ulnar deviation. In order to simplify the analysis, the initial and final shape and position of the median nerve were measured and analyzed. The circularity of the median nerve was significantly increased and the aspect ratio and perimeter were significantly decreased in the final image compared to that in the first image during wrist flexion with finger extension, wrist flexion with finger flexion and wrist ulnar deviation with finger extension (p<0.01). There were significant differences in median nerve displacement vector between finger flexion, wrist flexion with finger extension and wrist ulnar deviation with finger extension (all p<0.001). The mean amplitudes of the median nerve motion in wrist flexion with finger extension (2.36±0.79 NU), wrist flexion with finger flexion (2.46±0.84 NU) and wrist ulnar deviation with finger extension (2.86±0.51 NU) were higher than those in finger flexion (0.82±0.33 NU), wrist extension with finger extension (0.77±0.46 NU) and wrist extension with finger flexion (0.81±0.58 NU) (p<0.0001). In the normal carpal tunnel, wrist flexion and ulnar deviation could induce significant transverse displacement and deformation of the median nerve. PMID:24210862

  9. [Pathogenesis of lumbo-sacral nerve root lesion: from the view point of thermographic findings of the lower limbs].

    PubMed

    Igarashi, K

    1990-09-01

    Pathogenesis of the lumbo-sacral nerve roots lesion is discussed especially on the role of the sympathetic nerve using thermographic investigation of the lower limbs. 50 persons without any lumbar symptom were selected as control, and 97 patients with lumbo-sacral nerve roots lesion, including 64 with lumbar disc herniation (LDH) and 33 with lumbar canal stenosis (LCS), were the subjects of this study. In 33 patients group thermography was taken before and after selective nerve root block. The thermograms of the control group showed almost symmetrical thermatome. 49 (76.6%) of LDH group had hypothermal area on the affected limb, however, particularity of the hypothermal area did not define between L5 and S1 nerve root lesion. The patients with hypothermal area of the lower limb were characterised as having apparent neurological deficits and longer duration of the history from the onset, compared with the group without hypothermal area. 25 (75.8%) of LCS group showed not only hypothermal but also complicated thermographic findings. The patients with the complicated findings tended to have severer neurological deficits. Through thermographic findings after nerve root block, it is suggested that skin distribution of the particular nerve root, for example L5 or S1 nerve root distribution, exists in the lower limbs probably related to sympathetic nerve. This study concludes that thermograms of the lower limbs reflect pathogenesis of lumbo-sacral nerve root lesion in some extent, and probably indicate the prognosis of the lesion. PMID:1966740

  10. Blood flow analysis of compressed nerve root after intravenous injection of lipo-prostaglandin E1.

    PubMed

    Kobayashi, Shigeru; Baba, Hisatoshi; Takeno, Kenichi; Shimada, Seiichro; Kubota, Masafumi; Yayama, Takafumi; Miyazaki, Tsuyoshi; Uchida, Kenzo; Suzuki, Yoshihiko

    2009-09-01

    Prostaglandin E(1) (PGE(1)) is a potent vasodilator as well as an inhibitor of platelet aggregation and has therefore attracted interest as a therapeutic drug for lumbar canal stenosis. However, investigations in the clinical setting have shown that PGE(1) is effective in some patients but not in others, although the reason for this is unclear. The aim of the present study was to measure changes in intraradicular blood flow after intravenous injection of lipo-PGE(1) (0.15 microg/kg) using a laser Doppler flow meter in control model and nerve root compression model. Then, the nerve root in which blood flow was measured was removed and examined histologically. Intravenous injection of lipo-PGE(1) also resulted in marked increase of blood flow in the uncompressed nerve roots of the control group, but caused minimal enhancement of blood flow at the sites of nerve root compression exhibiting Wallerian degeneration. It is concluded that lipo-PGE(1) has less effect on markedly degenerated nerve roots than it does on those that are normal. PMID:19322792

  11. [Sciatica due to unusual causes: Tarlov cysts and nerve roots anomalies].

    PubMed

    Younes, M; Korbaa, W; Zrour, S; Bejia, I; Touzi, M; Bergaoui, N

    2009-03-01

    Tarlov cysts and nerve roots anomalies usually involve lumbosacral roots and are often asymptomatic. MRI has enabled recognition of many conditions that used to be missed by CT or myelography investigations performed for back and leg pain. However, even without additional compressive impingement (disc hernia, spondylolisthesis or lumbar canal stenosis) these anomalies can be responsible for sciatica, motor deficit and bladder sphincter dysfunction. Tarlov cysts are perinervous dilatations of the dorsal root ganglion. CT and especially MRI can reveal these cysts and their precise relations with the neighboring structures. Delayed filling of the cysts can be visualized on the myelogram. MRI is more sensitive than CT myelography for a positive diagnosis of nerve root anomalies, a differential diagnosis with disc hernia and classification of these anomalies. Surgical treatment is indicated for symptomatic Tarlov cysts and nerve root anomalies resistant to conservative treatment. Better outcome is observed in patients with an additional compressive impingement component. We report two cases of sciatica: one caused by Tarlov cysts diagnosed by MRI and the other by nerve root anomalies diagnosed by CT myelography. In both cases, conservative treatment was undertaken. The clinical, radiological and therapeutic aspects of these disorders are discussed. PMID:18809189

  12. [Chronic inflammatory demyelinating polyradiculoneuropathy with hypertrophy of cervico-thoracal nerve roots in a dog].

    PubMed

    Kathmann, I; Böttcher, I Ch; von Klopmann, T; Gerdwilker, A; Tipold, A

    2006-06-01

    A case of chronic inflammatory demyelinating polyradiculoneuropathy in a Magyar Vizsla dame, 7 months of age, is described. The neurological deficits such as movement disorders, hyporeflexia and muscle atrophy, were limited to the front legs. The hypertrophied cervico-thoracal nerve roots could be shown by magnetic resonance imaging. The diagnosis was additionally based on clinical findings, the relapsing course, the good response to therapy with prednisolone, the results of electrodiagnostic workup and muscle and nerve biopsy. PMID:16826707

  13. Muscle hypertrophy due to scarring of the S1 nerve root.

    PubMed

    Heuss, D; Schober, S; Eberhardt, K; Probst-Cousin, S; Kayser, C; Hecht, M; Huk, W; Neundörfer, B

    2000-07-01

    Segmental muscle enlargement occurs in a variety of neurogenic conditions. We present a patient with calf hypertrophy, likely produced by continuous neuromuscular irritability and compensatory type 1 and type 2 muscle fiber hypertrophy. The underlying lesion of the S1 nerve root was caused by scarring, which could be demonstrated by Gadolinum enhanced, fat saturated magnetic resonance imaging. Thus, the application of this technique is recommended in otherwise etiologically unclear cases of neurogenic muscular lesions in order to detect chronic nerve root pathology. PMID:10935218

  14. Development of a duration threshold for modulating evoked neuronal responses after nerve root compression injury.

    PubMed

    Nicholson, Kristen J; Quindlen, Julia C; Winkelstein, Beth A

    2011-11-01

    Cervical nerve roots are susceptible to compression injuries of various durations. The duration of an applied compression has been shown to contribute to both the onset of persistent pain and also the degree of spinal cellular and molecular responses related to nociception. This study investigated the relationship between peripherally-evoked activity in spinal cord neurons during a root compression and the resulting development of axonal damage. Electrically-evoked spikes were measured in the spinal cord as a function of time during and after (post-compression) a 15 minute compression of the C7 nerve root. Compression to the root significantly (p=0.035) reduced the number of spikes that were evoked over time relative to sham. The critical time for compression to maximally reduce evoked spikes was 6.6±3.0 minutes. A second study measured the post- compression evoked neuronal activity following compression applied for a shorter, sub-threshold time (three minutes). Ten minutes after compression was removed, the discharge rate remained significantly (p=0.018) less than baseline by 58±25% relative to sham after the 15 minute compression, but returned to within 3±33% of baseline after the three minute compression. Axonal damage was evident in the nerve root at day seven after nerve root compression only after a 15 minute compression. These studies demonstrate that even a transient mechanical insult to the nerve root is sufficient to induce sustained neuronal dysfunction and axonal pathology associated with pain, and results provide support that such minor neural tissue traumas can actually induce long-lasting functional deficits. PMID:22869302

  15. Selective hypertrophy of the cauda equina nerve roots.

    PubMed

    Burton, Matthew; Anslow, Philip; Gray, Winifred; Donaghy, Michael

    2002-03-01

    Two patients are described with a previously unreported hypertrophic radiculopathy of the cauda equina with preservation of peripheral nerve function. In one removal of an associated bronchial carcinoid tumour led to marked improvement in the neurological condition suggesting a paraneoplastic cause. The second patient later developed an external ophthalmoplegia but the underlying aetiology remains obscure. PMID:11993535

  16. Rapid identification of anterior and posterior root of cauda equina nerves by near-infrared diffuse reflectance spectroscopy

    Microsoft Academic Search

    Shaofei Xie; Bingren Xiang; Shoushan Bu; Xiaojian Cao; Ye Ye; Jun Lu; Haishan Deng

    2009-01-01

    A new rapid chemometric method has been developed to identify the anterior and posterior roots of cauda equina nerves by near-infrared (NIR) diffuse reflectance spectroscopy. NIR spectra of nerves were measured using a Fourier transform NIR spectrometer equipped with a fiber-optic probe. The result revealed no observable difference in the spectra between the anterior and posterior root samples, but the

  17. Differences between Cervical Schwannomas of the Anterior and Posterior Nerve Roots in Relation to the Incidence of Postoperative Radicular Dysfunction

    PubMed Central

    Ohnishi, Yu-Ichiro; Ohkawa, Toshika; Ninomiya, Koshi; Moriwaki, Takashi; Yoshimine, Toshiki

    2015-01-01

    Study Design A retrospective study. Purpose To assess the case files of patients who underwent surgery for cervical dumbbell schwannoma for determining the differences between schwannomas of the anterior and posterior nerve roots with respect to the incidence of postoperative radicular dysfunction. Overview of Literature The spinal roots giving origin to schwannoma are frequently nonfunctional, but there is a risk of postoperative neurological deficit once these roots are resected during surgery. Methods Fifteen patients with cervical dumbbell schwannomas were treated surgically. Ten men and 5 women, who were 35-79 years old (mean age, 61.5 years), presented with neck pain (n=6), radiculopathy (n=10), and myelopathy (n=11). Results Fourteen patients underwent gross total resection and exhibited no recurrence. Follow-ups were performed for a period of 6-66 months (mean, 28 months). Preoperative symptoms resolved in 11 patients (73.3%) but they persisted partially in 4 patients (26.7%). Six patients had tumors of anterior nerve root origin, and 9 patients had tumors of posterior nerve root origin. Two patients who underwent total resection of anterior nerve root tumors (33.3%) displayed minor postoperative motor weakness. One patient who underwent total resection of a posterior nerve root tumor (11.1%) showed postoperative numbness. Conclusions Appropriate tumor removal improved the neurological symptoms. In this study, the incidence of radicular dysfunction was higher in patients who underwent resection of anterior nerve root tumors than in patients who underwent resection of posterior nerve root tumors. PMID:25901239

  18. Bony spinal canal changes that differentiate conjoined nerve roots from herniated nucleus pulposus

    SciTech Connect

    Hoddick, W.K.; Helms, C.A.

    1985-01-01

    CT examinations of the lumbar spine in 12 consecutive patients with conjoined nerve roots were reviewed. Asymmetry of the bony spinal canal, seen as slight dilatation of the ipsilateral lateral recess, was present in all cases. This finding, which is not typically associated with extruded free intervertebral disk fragments, should serve to distinguish these two entities.

  19. Lack of effectiveness of laser therapy applied to the nerve course and the correspondent medullary roots

    PubMed Central

    Sousa, Fausto Fernandes de Almeida; Ribeiro, Thaís Lopes; Fazan, Valéria Paula Sassoli; Barbieri, Claudio Henrique

    2013-01-01

    OBJECTIVE: To investigate the influence of low intensity laser irradiation on the regeneration of the fibular nerve of rats after crush injury. METHODS: Twenty-five rats were used, divided into three groups: 1) intact nerve, no treatment; 2) crushed nerve, no treatment; 3) crush injury, laser irradiation applied on the medullary region corresponding to the roots of the sciatic nerve and subsequently on the course of the damaged nerve. Laser irradiation was carried out for 14 consecutive days. RESULTS: Animals were evaluated by functional gait analysis with the peroneal functional index and by histomorphometric analysis using the total number of myelinated nerve fibers and their density, total number of Schwann cells, total number of blood vessels and the occupied area, minimum diameter of the fiber diameter and G-quotient. CONCLUSION: According to the statistical analysis there was no significant difference among groups and the authors conclude that low intensity laser irradiation has little or no influence on nerve regeneration and functional recovery. Laboratory investigation. PMID:24453650

  20. Substance P and calcitonin gene-related peptide expression in dorsal root ganglia in sciatic nerve injury rats

    PubMed Central

    Fu, Changma; Yin, Zongsheng; Yu, Defu; Yang, Zuhua

    2013-01-01

    The neuropeptides, substance P and calcitonin gene-related peptide, have been shown to be involved in pain transmission and repair of sciatic nerve injury. A model of sciatic nerve defect was prepared by dissecting the sciatic nerve at the middle, left femur in female Sprague Dawley rats. The two ends of the nerve were encased in a silica gel tube. L5 dorsal root ganglia were harvested 7, 14 and 28 days post sciatic nerve injury for immunohistochemical staining. Results showed that substance P and citonin gene-related peptide expression increased significantly in dorsal root ganglion of rats with sciatic nerve injury. This increase peaked at 7 days, declined at 14 days, and reduced to normal levels by 28 days post injury. The findings indicate that the neuropeptides, substance P and calcitonin gene- related peptide, mainly increased in the early stages after sciatic nerve injury. PMID:25206633

  1. Migratory Reed Warblers Need Intact Trigeminal Nerves to Correct for a 1,000 km Eastward Displacement.

    PubMed

    Kishkinev, Dmitry; Chernetsov, Nikita; Heyers, Dominik; Mouritsen, Henrik

    2013-01-01

    Several studies have shown that experienced night-migratory songbirds can determine their position, but it has remained a mystery which cues and sensory mechanisms they use, in particular, those used to determine longitude (east-west position). One potential solution would be to use a magnetic map or signpost mechanism like the one documented in sea turtles. Night-migratory songbirds have a magnetic compass in their eyes and a second magnetic sense with unknown biological function involving the ophthalmic branch of the trigeminal nerve (V1). Could V1 be involved in determining east-west position? We displaced 57 Eurasian reed warblers (Acrocephalus scirpaceus) with or without sectioned V1. Sham operated birds corrected their orientation towards the breeding area after displacement like the untreated controls did. In contrast, V1-sectioned birds did not correct for the displacement. They oriented in the same direction after the displacement as they had done at the capture site. Thus, an intact ophthalmic branch of the trigeminal nerve is necessary for detecting the 1,000 km eastward displacement in this night-migratory songbird. Our results suggest that V1 carries map-related information used in a large-scale map or signpost sense that the reed warblers needed to determine their approximate geographical position and/or an east-west coordinate. PMID:23840374

  2. Migratory Reed Warblers Need Intact Trigeminal Nerves to Correct for a 1,000 km Eastward Displacement

    PubMed Central

    Heyers, Dominik; Mouritsen, Henrik

    2013-01-01

    Several studies have shown that experienced night-migratory songbirds can determine their position, but it has remained a mystery which cues and sensory mechanisms they use, in particular, those used to determine longitude (east–west position). One potential solution would be to use a magnetic map or signpost mechanism like the one documented in sea turtles. Night-migratory songbirds have a magnetic compass in their eyes and a second magnetic sense with unknown biological function involving the ophthalmic branch of the trigeminal nerve (V1). Could V1 be involved in determining east–west position? We displaced 57 Eurasian reed warblers (Acrocephalus scirpaceus) with or without sectioned V1. Sham operated birds corrected their orientation towards the breeding area after displacement like the untreated controls did. In contrast, V1-sectioned birds did not correct for the displacement. They oriented in the same direction after the displacement as they had done at the capture site. Thus, an intact ophthalmic branch of the trigeminal nerve is necessary for detecting the 1,000 km eastward displacement in this night-migratory songbird. Our results suggest that V1 carries map-related information used in a large-scale map or signpost sense that the reed warblers needed to determine their approximate geographical position and/or an east–west coordinate. PMID:23840374

  3. Intracerebroventricular Administration of Nerve Growth Factor Induces Gliogenesis in Sensory Ganglia, Dorsal Root, and within the Dorsal Root Entry Zone

    PubMed Central

    Schlachetzki, Johannes C. M.; Pizzo, Donald P.; Morrissette, Debbi A.; Winkler, Jürgen

    2014-01-01

    Previous studies indicated that intracerebroventricular administration of nerve growth factor (NGF) leads to massive Schwann cell hyperplasia surrounding the medulla oblongata and spinal cord. This study was designed to characterize the proliferation of peripheral glial cells, that is, Schwann and satellite cells, in the trigeminal ganglia and dorsal root ganglia (DRG) of adult rats during two weeks of NGF infusion using bromodeoxyuridine (BrdU) to label dividing cells. The trigeminal ganglia as well as the cervical and lumbar DRG were analyzed. Along the entire neuraxis a small number of dividing cells were observed within these regions under physiological condition. NGF infusion has dramatically increased the generation of new cells in the neuronal soma and axonal compartments of sensory ganglia and along the dorsal root and the dorsal root entry zone. Quantification of BrdU positive cells within sensory ganglia revealed a 2.3- to 3-fold increase in glial cells compared to controls with a similar response to NGF for the different peripheral ganglia examined. Immunofluorescent labeling with S100? revealed that Schwann and satellite cells underwent mitosis after NGF administration. These data indicate that intracerebroventricular NGF infusion significantly induces gliogenesis in trigeminal ganglia and the spinal sensory ganglia and along the dorsal root entry zone as well as the dorsal root. PMID:24738070

  4. Spinal cord and spinal nerve root involvement (myeloradiculopathy) in tuberculous meningitis.

    PubMed

    Gupta, Rahul; Garg, Ravindra Kumar; Jain, Amita; Malhotra, Hardeep Singh; Verma, Rajesh; Sharma, Praveen Kumar

    2015-01-01

    Most of the information about spinal cord and nerve root involvement in tuberculous meningitis is available in the form of isolated case reports or case series. In this article, we evaluated the incidence, predictors, and prognostic impact of spinal cord and spinal nerve root involvement in tuberculous meningitis.In this prospective study, 71 consecutive patients of newly diagnosed tuberculous meningitis were enrolled. In addition to clinical evaluation, patients were subjected to magnetic resonance imaging (MRI) of brain and spine. Patients were followed up for at least 6 months.Out of 71 patients, 33 (46.4%) had symptoms/signs of spinal cord and spinal nerve root involvement, 22 (30.9%) of whom had symptoms/signs at enrolment. Eleven (15.4%) patients had paradoxical involvement. Paraparesis was present in 22 (31%) patients, which was of upper motor neuron type in 6 (8.4%) patients, lower motor neuron type in 10 (14%) patients, and mixed type in 6 (8.4%) patients. Quadriparesis was present in 3 (4.2%) patients. The most common finding on spinal MRI was meningeal enhancement, seen in 40 (56.3%) patients; in 22 (30.9%), enhancement was present in the lumbosacral region. Other MRI abnormalities included myelitis in 16 (22.5%), tuberculoma in 4 (5.6%), cerebrospinal fluid (CSF) loculations in 4 (5.6%), cord atrophy in 3 (4.2%), and syrinx in 2 (2.8%) patients. The significant predictor associated with myeloradiculopathy was raised CSF protein (>250?mg/dL). Myeloradiculopathy was significantly associated with poor outcome.In conclusion, spinal cord and spinal nerve root involvement in tuberculous meningitis is common. Markedly raised CSF protein is an important predictor. Patients with myeloradiculopathy have poor outcome. PMID:25621686

  5. Congenital absence of lumbosacral articular facet joint associated with conjoined nerve root: a case report

    Microsoft Academic Search

    Shinji Yoshioka; Koichi Sairyo; Toshinori Sakai; Natsuo Yasui

    2010-01-01

    We report a rare case of congenital absence of the L5-S1 facet joint, which was associated with a conjoined nerve root. Combination\\u000a of these two anomalies has been quite rarely reported in the literature. A 39-year-old man presented with acute low back pain\\u000a and right leg radiating pain. Muscle weakness and sensory disturbance of the right leg were also apparent

  6. Potential risk of thermal damage to cervical nerve roots by a high-speed drill.

    PubMed

    Hosono, N; Miwa, T; Mukai, Y; Takenaka, S; Makino, T; Fuji, T

    2009-11-01

    Using the transverse processes of fresh porcine lumbar spines as an experimental model we evaluated the heat generated by a rotating burr of a high-speed drill in cutting the bone. The temperature at the drilled site reached 174 degrees C with a diamond burr and 77 degrees C with a steel burr. With water irrigation at a flow rate of 540 ml/hr an effective reduction in the temperature was achieved whereas irrigation with water at 180 ml/hr was much less effective. There was a significant negative correlation between the thickness of the residual bone and the temperature measured at its undersurface adjacent to the drilling site (p < 0.001). Our data suggest that tissues neighbouring the drilled bone, especially nerve roots, can be damaged by the heat generated from the tip of a high-speed drill. Nerve-root palsy, one of the most common complications of cervical spinal surgery, may be caused by thermal damage to nerve roots arising in this manner. PMID:19880905

  7. Pleural malignant mesothelioma causing cord infiltration through the nerve root. Case report.

    PubMed

    Okura, Hidehiro; Suga, Yasuo; Akiyama, Osamu; Kudo, Kentaro; Tsutsumi, Satoshi; Abe, Yusuke; Yasumoto, Yukimasa; Ito, Masanori; Izumi, Hiroshi; Shiomi, Kazu

    2009-04-01

    A 61-year-old man presented with a rare pleural malignant mesothelioma of the spine manifesting as progressive weakness of the bilateral lower extremities, numbness in the body and both legs, and dysfunction of the bladder and bowel. He had previous occupational exposure to asbestos while working at a car repair shop and had undergone right panpleuropneumonectomy under a diagnosis of sarcomatous type mesothelioma in the right pleural space. Magnetic resonance imaging of the spine with gadolinium showed an enhanced intramedullary tumor at the T4 level. Operative findings disclosed the clouded and swollen right posterior nerve root, and the pial surface was covered by clouded arachnoid-like membrane. The removed part of the T4 posterior nerve root and intramedullary tumor revealed malignant mesothelioma with invasion spreading along the posterior nerve root. He died of respiratory failure 3 months after the diagnosis. This case shows that spinal metastasis must be considered if a patient with pleural malignant mesothelioma shows neurological worsening and neuroimaging shows an abnormal lesion in the thoracic spinal cord. However, the patient's neurological condition is very difficult to improve in the presence of spinal cord infiltration. PMID:19398862

  8. Microsurgical anatomy of the denticulate ligaments and their relationship with the axilla of the spinal nerve roots.

    PubMed

    Gürer, Bora; Canbay, Suat; Bozkurt, Melih; Cikla, Ula?; Hananya, Tomer; Okut, Hayrettin; Ba?kaya, Mustafa K

    2014-07-01

    The denticulate ligaments (DL), 20 or 21 pairs of meningeal extensions, spread from the lateral aspect of the spinal cord to the internal aspect of the spinal dura mater. The aim of this study is to define the specific relationship of the DL with adjacent axilla of the spinal nerve roots and to investigate the anatomical features of the DLs and their variations. The topographical anatomy of the DLs and their relationships with the adjacent axilla of the spinal nerve roots was examined on 16 formalin-fixed adult cadaveric spinal cords. The distances from the dural attachment of the DL to the axilla of the superior and inferior spinal nerve roots were measured bilaterally at every spinal level. Also the distances from the dural attachment of the DL to the lateral aspect of the spinal cord were measured bilaterally. Cervical DLs showed a triangular shape, while in the thoracic segment the ligament changes the shape to "Y." Also the most caudal DL was identified to be at the L1-2 level. Our study revealed that the distances from the dural attachment of the DL to the superior and inferior spinal nerve root axilla were different at the cervical, upper thoracic and the lower thoracic segments. Both distances to the superior and inferior spinal nerve root axilla were shown to increase from cervical to lower thoracic segments. This study provides a detailed anatomy of the DLs and their relationship with the adjacent spinal nerve root axilla. PMID:23897545

  9. [Case of Charcot-Marie-Tooth disease type 1A with increased cerebrospinal fluid proteins and nerve root hypertrophy].

    PubMed

    Ishigami, Noriko; Kondo, Masaki; Nakagawa, Masanori

    2008-06-01

    We report herein a 54-year-old man who first noticed muscle weakness of the hands and legs and hypesthesia of the legs at 20-years-old. Symptoms gradually worsened. Charcot-Marie-Tooth disease type 1A (CMT 1A) was diagnosed on the basis of a nerve conduction study and PMP22 gene duplication. Increased levels of cerebrospinal fluid proteins were identified and cervical and lumbosacral nerve root hypertrophy was evident on magnetic resonance imaging (MRI). CMT 1A with increased CSF proteins and nerve root hypertrophy was carefully evaluated clinically and electrophysiologically to rule out other motor sensory neuropathies such as CIDP. Increased levels of CSF proteins in this case might have resulted from circulatory disturbance of CSF in hypertrophic nerve roots. PMID:18616154

  10. Painful nerve injury upregulates thrombospondin-4 expression in dorsal root ganglia.

    PubMed

    Pan, Bin; Yu, Hongwei; Park, John; Yu, Yanhui Peter; Luo, Z David; Hogan, Quinn H

    2015-03-01

    Thrombospondin-4 (TSP4) belongs to a family of large, oligomeric extracellular matrix glycoproteins that mediate interactions between cells and interactions of cells with underlying matrix components. Recent evidence shows that TSP4 might contribute to the generation of neuropathic pain. However, there has been no systematic examination of TSP4 expression in the dorsal root ganglia (DRG) after injury. This study, therefore, investigates whether TSP4 protein level is changed in DRG after injury following spinal nerve ligation (SNL) and spared nerve injury in rats by performing Western blotting, immunohistochemistry, and immunocytochemistry. After nerve ligation, TSP4 protein level is upregulated in the axotomized somata of the fifth lumbar (L5) DRG. There is substantial additional TSP4 in the nonneuronal compartment of the L5 DRG that does not costain for markers of satellite glia, microglia, or Schwann cells and appears to be in the interstitial space. Evidence of intracellular overexpression of TSP4 persists in neurons dissociated from the L5 DRG after SNL. These findings indicate that, following peripheral nerve injury, TSP4 protein expression is elevated in the cytoplasm of axotomized sensory neurons and in the surrounding interstitial space. PMID:25327416

  11. Dorsal root ganglion myeloid zinc finger protein 1 contributes to neuropathic pain after peripheral nerve trauma.

    PubMed

    Li, Zhisong; Gu, Xiyao; Sun, Linlin; Wu, Shaogen; Liang, Lingli; Cao, Jing; Lutz, Brianna Marie; Bekker, Alex; Zhang, Wei; Tao, Yuan-Xiang

    2015-04-01

    Peripheral nerve injury-induced changes in gene transcription and translation in primary sensory neurons of the dorsal root ganglion (DRG) are considered to contribute to neuropathic pain genesis. Transcription factors control gene expression. Peripheral nerve injury increases the expression of myeloid zinc finger protein 1 (MZF1), a transcription factor, and promotes its binding to the voltage-gated potassium 1.2 (Kv1.2) antisense (AS) RNA gene in the injured DRG. However, whether DRG MZF1 participates in neuropathic pain is still unknown. Here, we report that blocking the nerve injury-induced increase of DRG MZF1 through microinjection of MZF1 siRNA into the injured DRG attenuated the initiation and maintenance of mechanical, cold, and thermal pain hypersensitivities in rats with chronic constriction injury (CCI) of the sciatic nerve, without affecting locomotor functions and basal responses to acute mechanical, heat, and cold stimuli. Mimicking the nerve injury-induced increase of DRG MZF1 through microinjection of recombinant adeno-associated virus 5 expressing full-length MZF1 into the DRG produced significant mechanical, cold, and thermal pain hypersensitivities in naive rats. Mechanistically, MZF1 participated in CCI-induced reductions in Kv1.2 mRNA and protein and total Kv current and the CCI-induced increase in neuronal excitability through MZF1-triggered Kv1.2 AS RNA expression in the injured DRG neurons. MZF1 is likely an endogenous trigger of neuropathic pain and might serve as a potential target for preventing and treating this disorder. PMID:25630025

  12. Sector computed tomographic spine scanning in the diagnosis of lumbar nerve root entrapment

    SciTech Connect

    Risius, B.; Modic, M.T.; Hardy, R.W. Jr.; Duchesneau, P.M.; Weinstein, M.A.

    1982-04-01

    The diagnosis of lumbar nerve root entrapment was made by sector computed tomography (CT) scanning in 25 patients whose myelograms were normal at the site of the CT scan abnormalities. Sector CT scanning demonstrates preoperatively which neural foramina are narrow. This information, correlated with the patient's history and physical examination, indicates which foramina should be operated on and prevents unnecessary exploration of normal neutral foramina. CT findings were confirmed surgically in 14 patients. Eleven of these 14 patients had excellent postoperative results and remain pain free.

  13. Differentiation of peripheral nerve functions and properties with spectral analysis and Karnovsky-Roots staining: a preliminary study

    PubMed Central

    Xu, Qintong; Chen, Zenggan; Li, Qiong; Liu, Haifei; Zhang, Jian; Yao, Wenhua; Zhang, Ren; Li, Qingli; Liu, Hongying; Zhang, Feng; Lineaweaver, William C

    2014-01-01

    Objective: The purpose of this study was to explore the possibility for analyzing and differentiating between motor and sensory functions of peripheral nerve axons using spectral technology. Methods: 10 ?m slide section of S1 anterior and posterior rabbit spinal nerve roots were made and then stained with Karnovsky-Roots method for molecular hyperspectral imaging microscopy analysis. In addition, Raman spectra data of nerve axons on each slide was collected after Karnovsky-Roots staining for 30 minutes. Results: Motor axons were differentiated from sensory axons in a nerve axon section hyperspectral image via Spectral angle mapper algorithm. Raman scatterings could be detected near 2110 cm-1, and 2155 cm-1 in motor axons after Karnvosky-Roots staining. The value of I2100/I1440 in motor axons are significantly different (P0.001) than in sensory axons after staining for 30 minutes. Conclusions: Motor and sensory nerve axons can be differentiated from their counterparts in 30 minutes by using Raman micro-spectroscopy analysis assisted with Karnovsky-Roots staining. PMID:25419356

  14. Treatment of neurogenic torticollis by microvascular lysis of the accessory nerve roots — indication, technique, and first results

    Microsoft Academic Search

    N. Freckmann; R. Hagenah; H.-D. Herrmann; D. Müller

    1981-01-01

    Summary For treatment of spasmodic torticollis (s.T.) microsurgical decompression of the intraspinal-intracranial portion of the accessory nerve (a.N.) has been performed in 11 patients with proved neurogenic lesions of the accessory nerve-dependent muscles. Neurogenic lesions were discovered by meticulous electromyographic (EMG) examination in 26 out of 32 patients with s.T. Based on the EMG findings the a.N. roots were exposed,

  15. Effects of ischemic phrenic nerve root ganglion injury on respiratory disturbances in subarachnoid hemorrhage: an experimental study

    PubMed Central

    Demir, Recep; Aygül, Recep; Kotan, Dilcan; Çalik, Muhammet

    2013-01-01

    Introduction Phrenic nerves have important roles on the management of respiration rhythm. Diaphragm paralysis is possible in phrenic nerve roots ischemia in subarachnoid hemorrhage (SAH). We examined whether there is a relationship between phrenic nerve root ischemia and respiratory disturbances in SAH. Material and methods This study was conducted on 5 healthy control and 14 rabbits with experimentally induced SAH by injecting autologous blood into their cisterna magna. Animals were followed up via monitors for detecting the heart and respiration rhythms for 20 days and then decapitaed by humanely. Normal and degenerated neuron densities of phrenic nerve root at the level of C4 dorsal root ganglia (C4DRG) were estimated by Stereological methods. Between the mean numerical density of degenerated neurons of C4DRG and respiratory rate/minute of groups were compared statistically. Results Phrenic nerve roots, artery and diaphragm muscles degeneration was detected in respiratory arrest developed animals. The mean neuronal density of C4DRG was 13272 ±1201/mm3 with a mean respiration rate of 23 ±4/min in the control group. The mean degenerated neuron density was 2.240 ±450/mm3 and respiration rhythm was 31 ±6/min in survivors. But, the mean degenerated neuron density was 5850 ±650/mm3 and mean respiration rhythm was 34 ±7/min in respiratory arrest developed animals (n = 7). A linear relationship was noticed between the degenerated neuron density of C4DRG and respiraton rate (r = –0.758; p < 0.001). Conclusions Phrenic nerve root ischemia may be an important factor in respiration rhythms deteriorations in SAH which has not been mentioned in the literature. PMID:24482661

  16. Ultrasonographic nerve enlargement of the median and ulnar nerves and the cervical nerve roots in patients with demyelinating Charcot-Marie-Tooth disease: distinction from patients with chronic inflammatory demyelinating polyneuropathy.

    PubMed

    Sugimoto, Takamichi; Ochi, Kazuhide; Hosomi, Naohisa; Takahashi, Tetsuya; Ueno, Hiroki; Nakamura, Takeshi; Nagano, Yoshito; Maruyama, Hirofumi; Kohriyama, Tatsuo; Matsumoto, Masayasu

    2013-10-01

    Demyelinating Charcot-Marie-Tooth disease (CMT) and chronic inflammatory demyelinating polyneuropathy (CIDP) are both demyelinating polyneuropathies. The differences in nerve enlargement degree and pattern at multiple evaluation sites/levels are not well known. We investigated the differences in nerve enlargement degree and the distribution pattern of nerve enlargement in patients with demyelinating CMT and CIDP, and verified the appropriate combination of sites/levels to differentiate between these diseases. Ten patients (aged 23-84 years, three females) with demyelinating CMT and 16 patients (aged 30-85 years, five females) with CIDP were evaluated in this study. The nerve sizes were measured at 24 predetermined sites/levels from the median and ulnar nerves and the cervical nerve roots (CNR) using ultrasonography. The evaluation sites/levels were classified into three regions: distal, intermediate and cervical. The number of sites/levels that exhibited nerve enlargement (enlargement site number, ESN) in each region was determined from the 24 sites/levels and from the selected eight screening sites/levels, respectively. The cross-sectional areas of the peripheral nerves were markedly larger at all evaluation sites in patients with demyelinating CMT than in patients with CIDP (p < 0.01). However, the nerve sizes of CNR were not significantly different between patients with either disease. When we evaluated ESN of four selected sites for screening from the intermediate region, the sensitivity and specificity to distinguish between demyelinating CMT and CIDP were 0.90 and 0.94, respectively, with the cut-off value set at four. Nerve ultrasonography is useful to detect nerve enlargement and can clarify morphological differences in nerves between patients with demyelinating CMT and CIDP. PMID:23821028

  17. Axotomized and Intact Muscle Afferents But No Skin Afferents Develop Ongoing Discharges of Dorsal Root Ganglion Origin after Peripheral Nerve Lesion

    Microsoft Academic Search

    Martin Michaelis; Xianguo Liu; Wilfrid Janig

    2000-01-01

    After peripheral nerve lesions, some axotomized afferent neu- rons develop ongoing discharges that originate in the dorsal root ganglion (DRG). We investigated in vivo which functional types of afferent neurons contributed to this ectopic activity. Six to twelve days after the gastrocnemius soleus (GS) nerve sup- plying skeletal muscle and the sural (SU) nerve supplying skin had been transected (experimental

  18. Generation of New Neurons in Dorsal Root Ganglia in Adult Rats after Peripheral Nerve Crush Injury

    PubMed Central

    2015-01-01

    The evidence of neurons generated ex novo in sensory ganglia of adult animals is still debated. In the present study, we investigated, using high resolution light microscopy and stereological analysis, the changes in the number of neurons in dorsal root ganglia after 30 days from a crush lesion of the rat brachial plexus terminal branches. Results showed, as expected, a relevant hypertrophy of dorsal root ganglion neurons. In addition, we reported, for the first time in the literature, that neuronal hypertrophy was accompanied by massive neuronal hyperplasia leading to a 42% increase of the number of primary sensory neurons. Moreover, ultrastructural analyses on sensory neurons showed that there was not a relevant neuronal loss as a consequence of the nerve injury. The evidence of BrdU-immunopositive neurons and neural progenitors labeled with Ki67, nanog, nestin, and sox-2 confirmed the stereological evidence of posttraumatic neurogenesis in dorsal root ganglia. Analysis of morphological changes following axonal damage in addition to immunofluorescence characterization of cell phenotype suggested that the neuronal precursors which give rise to the newly generated neurons could be represented by satellite glial cells that actively proliferate after the lesion and are able to differentiate toward the neuronal lineage. PMID:25722894

  19. Confocal imaging reveals three-dimensional fine structure difference between ventral and dorsal nerve roots

    NASA Astrophysics Data System (ADS)

    Wu, Yuxiang; Sui, Tao; Cao, Xiaojian; Lv, Xiaohua; Zeng, Shaoqun; Sun, Peng

    2011-05-01

    Peripheral nerve injury repair is one of the most challenging problems in neurosurgery, partially due to lack of knowledge of three-dimensional (3-D) fine structure and organization of peripheral nerves. In this paper, we explored the structures of nerve fibers in ventral and dorsal nerves with a laser scanning confocal microscopy. Thick tissue staining results suggested that nerve fibers have a different 3-D structure in ventral and dorsal nerves, and reconstruction from serial sectioning images showed that in ventral nerves the nerve fibers travel in a winding form, while in dorsal nerves, the nerve fibers form in a parallel cable pattern. These structural differences could help surgeons to differentiate ventral and dorsal nerves in peripheral nerve injury repair, and also facilitate scientists to get a deeper understanding about nerve fiber organization.

  20. Increased response to glutamate in small diameter dorsal root ganglion neurons after sciatic nerve injury.

    PubMed

    Gong, Kerui; Kung, Ling-Hsuan; Magni, Giulia; Bhargava, Aditi; Jasmin, Luc

    2014-01-01

    Glutamate in the peripheral nervous system is involved in neuropathic pain, yet we know little how nerve injury alters responses to this neurotransmitter in primary sensory neurons. We recorded neuronal responses from the ex-vivo preparations of the dorsal root ganglia (DRG) one week following a chronic constriction injury (CCI) of the sciatic nerve in adult rats. We found that small diameter DRG neurons (<30 µm) exhibited increased excitability that was associated with decreased membrane threshold and rheobase, whereas responses in large diameter neurons (>30 µm) were unaffected. Puff application of either glutamate, or the selective ionotropic glutamate receptor agonists alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and kainic acid (KA), or the group I metabotropic receptor (mGluR) agonist (S)-3,5-dihydroxyphenylglycine (DHPG), induced larger inward currents in CCI DRGs compared to those from uninjured rats. N-methyl-D-aspartate (NMDA)-induced currents were unchanged. In addition to larger inward currents following CCI, a greater number of neurons responded to glutamate, AMPA, NMDA, and DHPG, but not to KA. Western blot analysis of the DRGs revealed that CCI resulted in a 35% increase in GluA1 and a 60% decrease in GluA2, the AMPA receptor subunits, compared to uninjured controls. mGluR1 receptor expression increased by 60% in the membrane fraction, whereas mGluR5 receptor subunit expression remained unchanged after CCI. These results show that following nerve injury, small diameter DRG neurons, many of which are nociceptive, have increased excitability and an increased response to glutamate that is associated with changes in receptor expression at the neuronal membrane. Our findings provide further evidence that glutamatergic transmission in the periphery plays a role in nociception. PMID:24748330

  1. Increased Response to Glutamate in Small Diameter Dorsal Root Ganglion Neurons after Sciatic Nerve Injury

    PubMed Central

    Gong, Kerui; Kung, Ling-Hsuan; Magni, Giulia; Bhargava, Aditi; Jasmin, Luc

    2014-01-01

    Glutamate in the peripheral nervous system is involved in neuropathic pain, yet we know little how nerve injury alters responses to this neurotransmitter in primary sensory neurons. We recorded neuronal responses from the ex-vivo preparations of the dorsal root ganglia (DRG) one week following a chronic constriction injury (CCI) of the sciatic nerve in adult rats. We found that small diameter DRG neurons (<30 µm) exhibited increased excitability that was associated with decreased membrane threshold and rheobase, whereas responses in large diameter neurons (>30 µm) were unaffected. Puff application of either glutamate, or the selective ionotropic glutamate receptor agonists alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and kainic acid (KA), or the group I metabotropic receptor (mGluR) agonist (S)-3,5-dihydroxyphenylglycine (DHPG), induced larger inward currents in CCI DRGs compared to those from uninjured rats. N-methyl-D-aspartate (NMDA)-induced currents were unchanged. In addition to larger inward currents following CCI, a greater number of neurons responded to glutamate, AMPA, NMDA, and DHPG, but not to KA. Western blot analysis of the DRGs revealed that CCI resulted in a 35% increase in GluA1 and a 60% decrease in GluA2, the AMPA receptor subunits, compared to uninjured controls. mGluR1 receptor expression increased by 60% in the membrane fraction, whereas mGluR5 receptor subunit expression remained unchanged after CCI. These results show that following nerve injury, small diameter DRG neurons, many of which are nociceptive, have increased excitability and an increased response to glutamate that is associated with changes in receptor expression at the neuronal membrane. Our findings provide further evidence that glutamatergic transmission in the periphery plays a role in nociception. PMID:24748330

  2. GABAA receptor modulation in dorsal root ganglia in vivo affects chronic pain after nerve injury.

    PubMed

    Naik, A K; Pathirathna, S; Jevtovic-Todorovic, V

    2008-07-17

    Neuropathic pain (NPP) due to sensory nerve injury is, in part, the result of peripheral sensitization leading to a long-lasting increase in synaptic plasticity in the spinal dorsal horn. Thus, activation of GABA-mediated inhibitory inputs from sensory neurons could be beneficial in the alleviation of NPP symptoms. Dorsal root ganglia (DRG) conduct painful stimulation from the periphery to the spinal cord. Long-lasting down-regulation in GABA tone or sensitivity in DRG neurons has been reported in animals with neuropathy. To determine the function of GABA in DRG in the development of NPP, we examined how the acute pharmacological GABA(A)-receptor modulation of L5 DRG in vivo affects the development of NPP in rats with crush injury to the sciatic nerve. Direct application of muscimol and gaboxadol, GABA(A) agonists, to L5 DRG immediately after injury induced dose-dependent alleviation, whereas bicuculline and picrotoxin, GABA(A) antagonists, worsened NPP postaxonal injury. The pain-alleviating effects of muscimol and gaboxadol were blocked by bicuculline. Muscimol, applied at the time of injury, caused complete and long-lasting abolishment of NPP development. However, when muscimol was applied after NPP had already developed, its pain-alleviating effect, although significant, was short-lived. Using a fluorescent tracer, sodium fluorescein, we confirmed that local DRG application results in minimal spread into the corresponding dorsal horn of the ipsilateral spinal cord. GABA(A) receptors in DRG are important in the development of NPP after peripheral nerve injury, making timely exogenous GABAergic manipulation at the DRG level a potentially useful therapeutic modality. PMID:18554816

  3. Movements elicited by electrical stimulation of muscles, nerves, intermediate spinal cord, and spinal roots in anesthetized and decerebrate cats

    Microsoft Academic Search

    Yoichiro Aoyagi; Vivian K. Mushahwar; Richard B. Stein; Arthur Prochazka

    2004-01-01

    Electrical stimulation offers the possibility of restoring motor function of paralyzed limbs after spinal-cord injury or stroke, but few data are available to compare possible sites of stimulation, such as muscle, nerve, spinal roots, or spinal cord. The aim of this study was to establish some characteristics of stimulation at these sites in the anesthetized and midcollicular decerebrate cat. The

  4. Differential effects of distal and proximal nerve lesions on carbonic anhydrase activity in rat primary sensory neurons, ventral and dorsal root axons

    Microsoft Academic Search

    J. M. Peyronnard; L. F. Charron; J. P. Messier; J. Lavoie

    1988-01-01

    The effect of proximal and distal peripheral nerve injuries on the histochemistry of carbonic anhydrase (CA) in rat dorsal root ganglion (DRG) neurons, and myelinated (MyF) dorsal and ventral root fibers was studied. Sciatic neurectomy induced no change. Contrariwise, 7 days after lumbar spinal nerve section the numbers of CA-stained ventral root MyF and DRG cells at the L4 and

  5. Comparative neurotoxic effects of root canal filling materials on rat sciatic nerve.

    PubMed

    Serper, A; Uçer, O; Onur, R; Etikan, I

    1998-09-01

    The neurotoxic effects of the root canal filling materials--Endomethasone, N2 Universal, Traitement SPAD, Sealapex, and Calciobiotic Root Canal Sealer (CRCS)--were investigated on isolated rat sciatic nerves after local application. All of the canal filling materials reversibly inhibited the compound action potential (cAP) amplitudes. N2 Universal produced a 50% inhibition in 4.2 +/- 0.2 min. Traitement SPAD, Endomethasone, and CRCS produced the same inhibition in 6.4 +/- 0.3, 6.5 +/- 0.2, and 6.6 +/- 1.1 min, and Sealapex in 9.2 +/- 2.0 min. The inhibitory effect of Sealapex decreased fastest, and 43% recovery of cAP amplitude was observed in 60 to 70 min. The inhibitory effects of Endomethasone, CRCS, and N2 Universal were more pronounced, and 10 to 20% recovery in cAP amplitudes were observed in 2 h. The inhibitory effect of Traitement SPAD was more persistent with 4% recovery in 2.5 h. PMID:9922746

  6. Irreducible dorsal distal radius fracture-dislocation with accompanying dorsal displacement of flexor tendons and median nerve: A rare type of injury

    PubMed Central

    Songür, Murat; ?ahin, Ercan; Zehir, Sinan; Kalem, Mahmut

    2014-01-01

    INTRODUCTION High energy distal radius fractures may cause significant soft tissue injuries. Dorsal displacement of median nerve and flexor tendons to dorsal compartment between distal radioulnar joint was an unreported type of soft tissue injury. PRESENTATION OF CASE 35-Year male admitted following fall from height diagnosed as closed distal radius fracture with dorsal displacement. The patient had no flexion and extension of all fingers with loss of sensation. Radial artery pulse was not palpable. Radiography and CT imaging revealed distal radius fracture with dorsal displacement with dorsal carpal dislocation. After failure of closed reduction, operative treatment was performed. At surgery, flexor tendons and median nerve was found to be placed at dorsal compartment. Reduction of the soft tissues was facilitated by distraction of distal radioulnar joint. DISCUSSION Dorsal displacement of volar structures as the result of fracture dislocation was found to be an unreported type of injury. Difficulty during reduction of dorsally displaced structures is an important feature of the case. CONCLUSION For severely displaced and deformed distal radial fractures and fracture dislocations, threshold for operative treatment should be kept low. PMID:25460459

  7. The comparative performance of Roots type aircraft engine superchargers as affected by change in impeller speed and displacement

    NASA Technical Reports Server (NTRS)

    Ware, Marsden; Wilson, Ernest E

    1929-01-01

    This report presents the results of tests made on three sizes of roots type aircraft engine superchargers. The impeller contours and diameters of these machines were the same, but the length were 11, 8 1/4, and 4 inches, giving displacements of 0.509, 0.382, and 0.185 cubic foot per impeller revolution. The information obtained serves as a basis for the examination of the individual effects of impeller speed and displacement on performance and of the comparative performance when speed and displacement are altered simultaneously to meet definite service requirements. According to simple theory, when assuming no losses, the air weight handled and the power required for a given pressure difference are directly proportional to the speed and the displacement. These simple relations are altered considerably by the losses. When comparing the performance of different sizes of machines whose impeller speeds are so related that the same service requirements are met, it is found that the individual effects of speed and displacement are canceled to a large extent, and the only considerable difference is the difference in the power losses which decrease with increase in the displacement and the accompanying decrease in speed. This difference is small in relation to the net power of the engine supercharger unit, so that a supercharger with short impellers may be used in those applications where the space available is very limited with any considerable sacrifice in performance.

  8. Paresis of the L5 nerve root after reduction of low-grade lumbosacral dysplastic spondylolisthesis: a case report.

    PubMed

    Lykissas, Marios G; Aichmair, Alexander; Widmann, Roger; Sama, Andrew A

    2014-09-01

    We present a unique case of a 16-year-old patient who underwent lumbar decompression surgery (L4-S1), low-grade spondylolisthesis reduction surgery at L5-S1, and posterior instrumented fusion from L4 to the pelvis. Neurologic monitoring did not show any sustained changes throughout the operation. The patient was awoken from endotracheal anesthesia with grade 0 muscle function of the left extensor hallucis longus and tibialis anterior muscles resulting in left-sided foot drop. At the last follow-up 12 months after surgery, the patient had partial recovery, with grade 4 muscle function of the left extensor hallucis longus and tibialis anterior muscles. We suggest that early identification with direct nerve root stimulation and wake-up test immediately after reduction of spondylolisthesis will allow prompt release of the reduction and further foramen exploration, and increase the possibility of good postoperative nerve root recovery. PMID:24887052

  9. Prostaglandin E1 but not corticosteroid increases nerve root blood flow velocity after lumbar diskectomy in surgical patients.

    PubMed

    Fukusaki, Makoto; Miyako, Masahiko; Miyoshi, Hiroshi; Takada, Masafumi; Terao, Yoshiaki; Konishi, Hiroaki; Sumikawa, Koji

    2003-04-01

    The purpose of this study was to clarify whether prostaglandin E1 (PGE(1)) or corticosteroid could increase blood flow in the nerve root because neurologic symptoms in spinal stenosis may be based on the vascular insufficiency in the nerve root. Fifty-seven patients undergoing lumbar diskectomy were randomly assigned to one of three groups. Each group received one of three protocols for intravenous injection: 10 mL of saline solution, group A (n = 19); 10 mL of PGE(1) (20 microg) solution, group B (n = 19); and 10 mL of dexamethasone (8 mg) solution, group C (n = 19). After lumbar diskectomy, a probe for laser Doppler flowmetry was placed directly on the lumbar nerve root. Nerve root blood flow (RBF) velocity and mean arterial pressure (MAP) were measured before injection (T0), 5 minutes after the start of injection (T1), 10 minutes after the start of injection (T2), and 10 minutes after the end of injection (T3). In groups A and C, these did not change throughout the time course. In group B, MAP decreased significantly at T1 (92%; P <.001), T2 (89%; P <.0001), and T3 (91%; P <.0001), while RBF velocity increased significantly at T1 (125%; P <.05), T2 (128%; P <.05), and T3 (121%; P <.05) compared with T0. The values in group B were different from those in group A (P <.05) and group C (P <.05) at T1 and T2. The results show that intravenous injection of low-dose PGE(1), but not corticosteroid, increases RBF velocity after lumbar diskectomy. PMID:12657990

  10. Effects of lipo-prostaglandin E 1 on blood flow and oxygen pressure in lumbo-sacral nerve roots

    Microsoft Academic Search

    Toshihiko Sekikawa; Masazumi Murakami; Kazuhisa Takahashi; Masatsune Yamagata; Koichi Yasuhara; Tetsuharu Nemoto; Toshio Suzuki; Haruaki Nakaya; Hideshige Moriya

    1997-01-01

    Lipo-prostaglandin E1 (lipo-PGE1) is reported to be effective in the treatment of intermittent neurogenic claudication associated with lumbar spinal stenosis.\\u000a However, the underlying mechanisms by which lipo-PGE1 improves the neurological symptoms have not been fully clarified. We examined the effects of lipo-PGE1 on blood flow and oxygen pressure in the lumbar nerve roots in cats and in patients with lumbar

  11. ?-diketone central neuropathy: quantitative morphometric analysis of axons in rat spinal cord white matter regions and nerve roots

    Microsoft Academic Search

    Richard M LoPachin; Bernard S Jortner; Maria L Reid; Soma Das

    2003-01-01

    A quantitative analytical method was used to measure myelinated axon morphometric parameters (e.g., axon area, ratio of axon area\\/fiber area, and index of circularity) in rat nervous tissue during intoxication with 2,5-hexanedione (HD). Parameters were assessed in nerve roots (dorsal and ventral) and in ascending (gracile fasciculus and spinocerebellar tract) and descending (corticospinal and rubrospinal tracts) spinal cord white matter

  12. Progesterone produces antinociceptive and neuroprotective effects in rats with microinjected lysophosphatidic acid in the trigeminal nerve root

    PubMed Central

    2012-01-01

    Background In our present study, we studied the role of demyelination of the trigeminal nerve root in the development of prolonged nociceptive behavior in the trigeminal territory. Results Under anesthesia, the Sprague-Dawley rats were mounted onto a stereotaxic frame and 3 ?L of lysophosphatidic acid (LPA, 1 nmol) was injected into the trigeminal nerve root to produce demyelination. This treatment decreased the air-puff thresholds, persisted until postoperative day 130, and then returned to the preoperative levels 160 days after LPA injection. The LPA-treated rats also showed a significant hyper-responsiveness to pin-prick stimulation. We further investigated the antinociceptive and neuroprotective effects of progesterone in rats undergoing demyelination of the trigeminal nerve root. Progesterone (8, 16 mg/kg/day) was administered subcutaneously, beginning on the operative day, for five consecutive days in the LPA-treated rats. Treatment with progesterone produced significant early anti-allodynic effects and delayed prolonged anti-allodynic effects. The expression of protein zero (P0) and peripheral myelin protein 22 (PMP22) were significantly down-regulated in the trigeminal nerve root on postoperative day 5 following LPA injection. This down-regulation of the P0 and PMP22 levels was blocked by progesterone treatment. Conclusions These results suggest that progesterone produces antinociceptive effects through neuroprotective action in animals with LPA-induced trigeminal neuropathic pain. Moreover, progesterone has potential utility as a novel therapy for trigeminal neuropathic pain relief at an appropriate managed dose and is therefore a possible future treatment strategy for improving the recovery from injury. PMID:22429647

  13. Slit-Robo GTPase-activating proteins are differentially expressed in murine dorsal root ganglia: modulation by peripheral nerve injury.

    PubMed

    Chen, Zhi-Bing; Zhang, Hai-Ying; Zhao, Jiu-Hong; Zhao, Wei; Zhao, Dan; Zheng, Lin-Feng; Zhang, Xian-Fang; Liao, Xiao-Ping; Yi, Xi-Nan

    2012-04-01

    The Slit-Robo GTPase-activating proteins (srGAPs) play an important role in neurite outgrowth and axon guidance; however, little is known about its role in nerve regeneration after injury. Here, we studied the expression of srGAPs in mouse dorsal root ganglia (DRG) following sciatic nerve transection (SNT) using morphometric and immunohistochemical techniques. Reverse transcriptase polymerase chain reaction and Western blot analysis indicated that srGAP1 and srGAP3, but not srGAP2, were expressed in normal adult DRG. Following unilateral SNT, elevated mRNA and protein levels of srGAP1 and srGAP3 were detected in the ipsilateral relative to contralateral L(3-4) DRGs from day 3 to day 14. Immunohistochemical results showed that srGAP1 and srGAP3 were largely expressed in subpopulations of DRG neurons in naïve DRGs. However, after SNT, srGAP3 in neurons was significantly increased in the ipsilateral relative to contralateral DRGs, which peaked at day 7 to day 14. Interestingly, DRG neurons with strong srGAP3 labeling also coexpressed Robo2 after peripheral nerve injury. These results suggest that srGAPs are differentially expressed in murine DRG and srGAP3 are the predominant form. Moreover, srGAP3 may participate in Slit-Robo signaling in response to peripheral nerve injury or the course of nerve regeneration. PMID:22271578

  14. Therapeutic selective nerve root block in the nonsurgical treatment of atraumatic cervical spondylotic radicular pain: A retrospective analysis with independent clinical review

    Microsoft Academic Search

    Curtis W. Slipman; Jason S. Lipetz; Howard B. Jackson; Denis P. Rogers; Edward J. Vresilovic

    2000-01-01

    Slipman CW, Lipetz JS, Jackson HB, Rogers DP, Vresilovic EJ. Therapeutic selective nerve root block in the nonsurgical treatment of atraumatic cervical Spondylotic radicular pain: a retrospective analysis with independent clinical review. Arch Phys Med Rehabil 2000;81:741–746.Objective: To investigate the outcomes resulting from the use of fluoroscopically guided therapeutic selective nerve root block (SNRB) in the nonsurgical treatment of atraumatic

  15. Surgical treatment for total root avulsion type brachial plexus injuries by neurotization: A prospective comparison study between total and hemicontralateral C7 nerve root transfer

    PubMed Central

    Tu, Yuan-Kun; Tsai, Yi-Jung; Chang, Chih-Han; Su, Fong-Chin; Hsiao, Chih-Kun; Tan, Jacqueline Siau-Woon

    2014-01-01

    Purpose: We conducted a clinical study to evaluate the effects of neurotization, especially comparing the total contralateral C7 (CC7) root transfer to hemi-CC7 transfer, on total root avulsion brachial plexus injuries (BPI). Methods: Forty patients who received neurotization for BPI were enrolled in this prospective study. Group 1 (n = 20) received hemi-CC7 transfer for hand function, while group 2 (n = 20) received total-CC7 transfer. Additional neurotization included spinal accessory, phrenic, and intercostal nerve transfer for shoulder and elbow function. The results were evaluated with an average of 6 years follow-up. Results: Group 1 had fewer donor site complications (15%) than group 2 (45%); group 2 had significantly better hand M3 and M4 motor function (65%) than group 1 (30%; P = 0.02). There was no difference in sensory recovery. Significantly, better shoulder function was obtained by simultaneous neurotization on both suprascapular and axillary nerves. Conclusions: Total-CC7 transfer had better hand recovery but more donor complications than hemi-CC7. Neurotization on both supra-scapular and axillary nerves improved shoulder recovery. © 2013 The Authors. Microsurgery published by Wiley Periodicals, Inc. Microsurgery 34:91–101, 2014. PMID:23913440

  16. MRI of the cervical nerve roots in the diagnosis of chronic inflammatory demyelinating polyradiculoneuropathy: a single-institution, retrospective case–control study

    PubMed Central

    Tanaka, Kanta; Mori, Nobuyuki; Yokota, Yusuke; Suenaga, Toshihiko

    2013-01-01

    Objective To systematically evaluate the usefulness of assessing the cervical nerve roots by MRI for the diagnosis of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Design Single-institution, retrospective case–control study. Setting A regional referral hospital. Participants We retrospectively enrolled 15 consecutive patients with CIDP who satisfied the European Federation of Neurological Societies/Peripheral Nerve Society (EFNS/PNS) typical and definite criteria and underwent cervical MRI. 30 control patients who had also undergone cervical MRI were included, matched with regard to sex, age and MRI system. The diagnoses of the control patients included cervical spondylosis (n=19), cervical spine trauma (n=2), infection (n=1), malignancies (n=4), demyelinating disorders (n=2) and neurodegenerative disorders (n=2). Measurement A radiologist determined the C5–C8 root diameters on the coronal short tau inversion recovery (STIR) images. Signal intensities of these roots were quantified as nerve-to-muscle contrast-to-noise ratios (CNRs), which were calculated using mean signal intensities of the roots and sternocleidomastoid muscle as well as SD of background noise. Statistical analyses were performed to determine the diagnostic accuracy of the diameters and nerve-to-muscle CNRs. Another radiologist reviewed MRI for ensuring reproducibility. Results The root diameters showed no significant differences between the patients with CIDP and control patients. The nerve-to-muscle CNRs were significantly higher in the patients with CIDP. We defined the sum of nerve-to-muscle CNRs of C5–C8 roots as the CNR score to serve as an index of overall signal intensity. The area under the receiver operating characteristic curve of CNR scores was 0.731. The reproducibility of the assessment procedure was satisfactory. Conclusions Our results suggest that assessment of the cervical nerve roots by MRI is useful for CIDP diagnosis when the signal intensities, rather than the diameters, are paid more attention on STIR images. PMID:23996823

  17. The Influence of Random Element Displacement on DOA Estimates Obtained with (Khatri–Rao-)Root-MUSIC

    PubMed Central

    Inghelbrecht, Veronique; Verhaevert, Jo; van Hecke, Tanja; Rogier, Hendrik

    2014-01-01

    Although a wide range of direction of arrival (DOA) estimation algorithms has been described for a diverse range of array configurations, no specific stochastic analysis framework has been established to assess the probability density function of the error on DOA estimates due to random errors in the array geometry. Therefore, we propose a stochastic collocation method that relies on a generalized polynomial chaos expansion to connect the statistical distribution of random position errors to the resulting distribution of the DOA estimates. We apply this technique to the conventional root-MUSIC and the Khatri-Rao-root-MUSIC methods. According to Monte-Carlo simulations, this novel approach yields a speedup by a factor of more than 100 in terms of CPU-time for a one-dimensional case and by a factor of 56 for a two-dimensional case. PMID:25393783

  18. The influence of random element displacement on DOA estimates obtained with (Khatri-Rao-)root-MUSIC.

    PubMed

    Inghelbrecht, Veronique; Verhaevert, Jo; van Hecke, Tanja; Rogier, Hendrik

    2014-01-01

    Although a wide range of direction of arrival (DOA) estimation algorithms has been described for a diverse range of array configurations, no specific stochastic analysis framework has been established to assess the probability density function of the error on DOA estimates due to random errors in the array geometry. Therefore, we propose a stochastic collocation method that relies on a generalized polynomial chaos expansion to connect the statistical distribution of random position errors to the resulting distribution of the DOA estimates. We apply this technique to the conventional root-MUSIC and the Khatri-Rao-root-MUSIC methods. According to Monte-Carlo simulations, this novel approach yields a speedup by a factor of more than 100 in terms of CPU-time for a one-dimensional case and by a factor of 56 for a two-dimensional case. PMID:25393783

  19. Sprouting from Chicken Embryo Dorsal Root Ganglia Induced by Nerve Growth Factor is Specifically Inhibited by Affinity-Purified Antiganglioside Antibodies

    Microsoft Academic Search

    M. Schwartz; N. Spirman

    1982-01-01

    The involvement of gangliosides in processes related to nerve regeneration and sprouting has been demonstrated recently. The type of interaction by which gangliosides may influence neuronal sprouting was investigated in the present work. Affinity-purified rabbit anti-GM1 antibodies were found to block the sprouting from dorsal root ganglia (DRG) of chicken embryo induced by nerve growth factor (NGF). Only a moderately

  20. Three-Dimensional Analysis of Nuclear Size, Shape and Displacement in Clover Root Cap Statocytes from Space and a Clinostat

    NASA Technical Reports Server (NTRS)

    Smith, J.D.; Todd, P. W.; Staehelin, L. A.; Holton, Emily (Technical Monitor)

    1997-01-01

    Under normal (l-g) conditions the statocytes of root caps have a characteristic polarity with the nucleus in tight association with the proximal cell wall; but, in altered gravity environments including microgravity (mu-g) and the clinostat (c-g) movement of the nucleus away from the proximal cell wall is not uncommon. To further understand the cause of gravity-dependent nuclear displacement in statocytes, three-dimensional cell reconstruction techniques were used to precisely measure the volumes, shapes, and positions of nuclei in white clover (Trifolium repens) flown in space and rotated on a clinostat. Seeds were germinated and grown for 72 hours aboard the Space Shuttle (STS-63) in the Fluid Processing Apparatus (BioServe Space Technologies, Univ. of Colorado, Boulder). Clinorotation experiments were performed on a two-axis clinostat (BioServe). Computer reconstruction of selected groups of statocytes were made from serial sections (0.5 microns thick) using the ROSS (Reconstruction Of Serial Sections) software package (Biocomputation Center, NASA Ames Research Center). Nuclei were significantly displaced from the tops of cells in mu-g (4.2 +/- 1.0 microns) and c-g (4.9 +/- 1.4 microns) when compared to l-g controls (3.4 +/- 0.8 gm); but, nuclear volume (113 +/- 36 cu microns, 127 +/- 32 cu microns and 125 +/- 28 cu microns for l-g, mu-g and c-g respectively) and the ratio of nuclear volume to cell volume (4.310.7%, 4.211.0% and 4.911.4% respectively) were not significantly dependent on gravity treatment (ANOVA; alpha = 0.05). Three-dimensional analysis of nuclear shape and proximity to the cell wall, however, showed that nuclei from l-g controls appeared ellipsoidal while those from space and the clinostat were more spherically shaped. This change in nuclear shape may be responsible for its displacement under altered gravity conditions. Since the cytoskeleton is known to affect nuclear polarity in root cap statocytes, those same cytoskeletal elements could also control nuclear shape. This alteration in nuclear shape and position in mu-g and c-g when compared to l-g may lead to functional differences in the gravity signaling systems of plants subjected to altered gravity environments.

  1. Use of an anal sphincter pressure monitor during operations on the sacral spinal cord and nerve roots.

    PubMed

    Pang, D; Casey, K

    1983-11-01

    The distinction of sacral roots and conus medullaris from lipoma, fibrous adhesions, and an abnormally thickened filum terminale can be difficult during operations on certain complicated dysraphic lesions. We describe a simple, noninvasive method of monitoring external anal sphincter "squeeze pressure" by means of an elongated, fluid-filled, polyethylene anal balloon connected to a pressure transducer. Cutaneous electrocardiographic (ECG) leads on both hips register the stimulus artifact from a monopolar nerve stimulator. The simultaneous display on the oscilloscope screen of the stimulus artifact and the resultant pressure response form an electromechanical coupling that allows the operator to identify a faulty stimulator probe and to distinguish true stimulus-induced external anal sphincter activity from spontaneous rhythmic contractions of the internal anal sphincter. Unilateral stimulation of the S-2, S-3, and S-4 roots generates tall pressure spikes between 40 and 75 torr in peak amplitudes, whereas S-1 and L-5 stimulation produces a stimulus artifact on the ECG but either no pressure response or a mere "ripple wave" of less than 7 torr. During operations on 11 patients with various dysraphic lesions, the S-2, S-3, and S-4 roots were identified easily and preserved, and the caudal extent of functioning neurons was localized within coni grossly distorted by intramedullary lipoma or chronic tethering. We prefer the anal sphincter pressure monitor to anal sphincter electromyography because of its simplicity, the inexpensive equipment, and its noise-free display that is virtually unaffected by other electronic systems in the operating room. PMID:6358936

  2. Selective detrusor activation by sacral ventral nerve-root stimulation: results of intraoperative testing in humans during implantation of a Finetech-Brindley system

    Microsoft Academic Search

    Nico J. M. Rijkhoff; Hessel Wijkstra; Philip E. V. van Kerrebroeck; Frans M. J. Debruyne

    1998-01-01

    Electrical sacral nerve-root stimulation can be used to induce bladder contraction. However, bladder emptying is hampered\\u000a by simultaneous contraction of the external urethral sphincter. Voiding may improve when using a stimulation method that allows\\u000a selective detrusor activation. Both theoretical and animal studies have demonstrated that it is possible to obtain selective\\u000a detrusor activation by sacral root stimulation using an selective

  3. Spinal intradural cystic venous angioma originating from a nerve root in the cauda equina.

    PubMed

    Nishimura, Yusuke; Hara, Masahito; Natsume, Atsushi; Nakajima, Yasuhiro; Fukuyama, Ryuichi; Wakabayashi, Toshihiko; Ginsberg, Howard J

    2013-12-01

    A spinal intradural extramedullary venous angioma is extremely rare and has not been previously reported. In this paper, the authors report on this entity with morphological and immunohistochemical evidence, and discuss the surgical strategy for its treatment. A 54-year-old woman presented to Nagoya University Hospital complaining of left-sided pain in the hip, thigh, and inguinal and perianal regions, with progressive worsening during the previous 2 weeks. Lumbar spine MRI showed an intradural extramedullary cyst at the level of T12-L1, which extended from the conus medullaris to the cauda equina. The cyst wall was not enhanced on T1-weighted MRI with Gd. Intraoperatively, a midline dural opening allowed the authors to easily visualize a dark-reddish cyst behind the spinal nerve rootlets in the cauda equina adjacent to the conus medullaris. The cyst was believed to originate from one of the spinal nerve rootlets in the cauda equina and a cluster of veins was identified on the cyst wall. The cyst was resected with the affected nerve rootlet. The surgery left no detectable neurological deficit. Based on the morphological and immunohistochemical evidence, the lesion was diagnosed as a venous angioma. No tumor recurrence was confirmed based on MRI at the time of the 2-year follow up. This is the first report of an intradural extramedullary cystic venous angioma that was successfully resected. PMID:24093468

  4. Ultrasound guided selective cervical nerve root block and superficial cervical plexus block for surgeries on the clavicle.

    PubMed

    Shanthanna, Harsha

    2014-05-01

    We report the anaesthetic management of two cases involving surgeries on the clavicle, performed under superficial cervical plexus block and selective C5 nerve root block under ultrasound (US) guidance, along with general anaesthesia. Regional analgesia for clavicular surgeries is challenging. Our patients also had significant comorbidities necessitating individualised approach. The first patient had a history of emphysema, obesity, and was allergic to morphine and hydromorphone. The second patient had clavicular arthritis and pain due to previous surgeries. He had a history of smoking, Stevens-Johnson syndrome, along with daily marijuana and prescription opioid use. Both patients had an effective regional block and required minimal supplementation of analgesia, both being discharged on the same day. Interscalene block with its associated risks and complications may not be suitable for every patient. This report highlights the importance of selective regional blockade and also the use of US guidance for an effective and safe block. PMID:25024480

  5. Correlation Between Vasodilatation and Secretion in the Lacrimal Gland Elicited by Stimulation of the Cornea and Facial Nerve Root of the Cat

    Microsoft Academic Search

    Tomoki Yasui; Keishiro Karita; Hiroshi Izumi; Makoto Tamai

    Purpose. To determine whether reflex vasodilatation can be elicited in the cat lacrimal gland by electrical stimulation of the cornea, whether the vasodilatation elicited by electrical stimula- tion of the facial nerve root found to be the efferent arm of the cornea-lacrimal gland reflex pathway correlates with the evoked secretion in the lacrimal gland, and what kind of receptors and

  6. Vasodilative effects of prostaglandin E1 derivate on arteries of nerve roots in a canine model of a chronically compressed cauda equina

    Microsoft Academic Search

    Masayoshi Shirasaka; Bunji Takayama; Miho Sekiguchi; Shin-ichi Konno; Shin-ichi Kikuchi

    2008-01-01

    BACKGROUND: Reduction of blood flow is important in the induction of neurogenic intermittent claudication (NIC) in lumbar spinal canal stenosis. PGE1 improves the mean walking distance in patients with NIC type cauda equina compression. PGE1 derivate might be effective in dilating blood vessels and improving blood flow in nerve roots with chronically compressed cauda equina. The aim of this study

  7. Effects of intrathecal anesthesia with different concentrations and doses on spinal cord, nerve roots and cerebrospinal fluid in dogs

    PubMed Central

    Guo, Jianrong; Lv, Na; Su, Yongjun; Liu, Yang; Zhang, Jianping; Yang, Dawei

    2014-01-01

    Objective: To investigate the effects of intrathecal anesthesia with bupivacaine, levobupivacaine and ropivacaine hydrochloride at different doses on the spinal cord, nerve roots and cerebrospinal fluid (CSF) in dogs. Methods: Forty-two mongrel dogs were randomly divided into normal saline group (C; 2 ml), 0.5% (B1) and 0.75% (B2) bupivacaine hydrochloride groups (2 ml), 0.5% (L1) and 0.75% (L2) levobupivacaine hydrochloride group (2 ml), 0.5% (R1) and 0.75% (R2) ropivacaine hydrochloride group (2 ml), and drugs were intrathecally injected. Results: The contents of Ca2+ and MDA and SOD activity of the spinal cord were comparable among groups (P > 0.05). In Groups B1, L1 and R1, the neuronal cytoplasm of spinal tissues was basically normal, the majority of mitochondria and endoplasmic reticulum had complete structure, and the lamellar structure of modulated fibers was nearly normal. In Groups B2, L2 and R2, a small amount of mitochondrial vacuolar degeneration was found in the neuronal cytoplasm of spinal cord, but their structures were basically normal; the neural tissues exhibited focal mild edema, and most of the lamellar structure of modulated fibers and Schwann cells were nearly normal except for loose structure in several fibers and cells. Conclusion: When compared with 0.75% anesthetics for local anesthesia, the early adverse effects on the ultrastructure of the spinal cord and nerve root reduce after focal anesthesia with 0.5% anesthetics. PMID:25664046

  8. gamma-diketone central neuropathy: quantitative morphometric analysis of axons in rat spinal cord white matter regions and nerve roots.

    PubMed

    LoPachin, Richard M; Jortner, Bernard S; Reid, Maria L; Das, Soma

    2003-11-15

    A quantitative analytical method was used to measure myelinated axon morphometric parameters (e.g., axon area, ratio of axon area/fiber area, and index of circularity) in rat nervous tissue during intoxication with 2,5-hexanedione (HD). Parameters were assessed in nerve roots (dorsal and ventral) and in ascending (gracile fasciculus and spinocerebellar tract) and descending (corticospinal and rubrospinal tracts) spinal cord white matter tracts (L4-L5) of rats intoxicated with HD at two different daily dose-rates (175 or 400 mg HD/kg/day, gavage). For each dose-rate, tissue was sampled at four neurological endpoints: unaffected, slight, moderate, and severe toxicity, as determined by gait analysis and measurements of grip strength. Results indicate that, regardless of the HD dose-rate, axon atrophy (reduced axon area) was a widespread, abundant effect that developed in concert with neurological deficits. The atrophy response occurred contemporaneously in both ascending and descending spinal tracts, which suggests that loss of caliber developed simultaneously along the proximodistal axon axis. In contrast, swollen axons were a numerically small component and were present in nerve roots and spinal tracts only during subchronic intoxication at the lower HD dose-rate (i.e., 175 mg/kg/day). Intoxication at the higher dose-rate (400 mg/kg/day) produced neurological deficits in the absence of axonal swellings. These observations in conjunction with our previous studies of HD-induced peripheral neuropathy (Toxicol. Appl. Pharmacol. 135 (1995) 58; and Toxicol. Appl. Pharmacol. 165 (2000) 127) indicate that axon atrophy, and not axonal swelling, is a primary neuropathic phenomenon. PMID:14613714

  9. Neurotrophic and neuroprotective actions of Achyranthes bidentata polypeptides on cultured dorsal root ganglia of rats and on crushed common peroneal nerve of rabbits.

    PubMed

    Cheng, Qiong; Yuan, Ying; Sun, Changnan; Gu, Xiaosong; Cao, Zheng; Ding, Fei

    2014-03-01

    We have isolated Achyranthes bidentata Blume polypeptides (ABPP) from the aqueous extract of A. bidentata Blume, a traditional Chinese medicine with multiple therapeutic applications. In this study, we aimed to investigate neurotrophic effects of ABPP on cultured dorsal root ganglia (DRGs) of rats and neuroprotective effects on crushed common peroneal nerve of rabbits. Immunochemistry and Western blot analysis indicated that ABPP (0.01, 0.1, and 1.0 ?g/ml) encouraged neurite outgrowth from cultured DRG explants/neurons in a concentration-dependent manner through activation of ERK1/2. After crush injury to rabbit common peroneal nerve, animals received daily administration of ABPP for 5 weeks. Electrophysiological assessments and histomorphological evaluation showed that 6.0mg/kg ABPP significantly enhanced nerve regeneration and function restoration. Our findings suggest that ABPP could be used as a neurotrophic and neuroprotective agent to treat peripheral nerve crush injury. PMID:24361134

  10. Dejerine-Sottas neuropathy with multiple nerve roots enlargement and hypomyelination associated with a missense mutation of the transmembrane domain of MPZ/P0.

    PubMed

    Simonati, Alessandro; Fabrizi, Gian Maria; Taioli, Federica; Polo, Alberto; Cerini, Roberto; Rizzuto, Nicolò

    2002-09-01

    In a patient affected with a slowly progressive, severe form of Dejerine-Sottas syndrome, symmetric enlargement of cranial nerves and focal hypertrophy of cervical and caudal roots were detected following MRI. Neuropathological features of the sural nerve disclosed a dramatic loss of myelinated fibres, with skewed-to-the-left, unimodal distribution of the few residual fibres, consistent with the diagnosis of congenital hypomyelination neuropathy. Genetic analysis revealed this condition to be associated with a heterozygous G to A transition at codon 167 in the exon 4 of the MPZ/P0 gene causing a Gly138Arg substitution in the transmembrane domain of the mature MPZ/P0 protein. Focal enlargement of the nerve trunks in demyelinating, hereditary motor and sensory neuropathies (HMSN) was previously reported in both asymptomatic and symptomatic cases with root compression, but peculiar to this case is the diffuse involvement of both cranial and spinal nerves. We believe that the relevance of nerve trunk hypertrophy in HMSN is probably underevaluated: therefore MRI investigation of the head and spine should be included in the diagnostic study of selected HMSN patients. Molecular analysis of peripheral myelin genes will help to rule out misdiagnosed cases. PMID:12242557

  11. Slowed motor conduction in lumbosacral nerve roots in cauda equina lesions: a new diagnostic technique

    Microsoft Academic Search

    M Swash; S J Snooks

    1986-01-01

    New techniques have been developed for the electrophysiological assessment of patients with suspected cauda equina lesions using transcutaneous spinal stimulation (500-1500 V: time constant 50 microseconds) to measure motor latencies to the external and sphincter and puborectalis muscles from L1 and L4 vertebral levels. These latencies represent motor conduction in the S3 and S4 motor roots of the cauda equina

  12. Intraobserver and interobserver reproducibility of the novel transcription method for selection of potential nerve root compression in MRI study in degenerative disease of the lumbar spine

    PubMed Central

    Kubaszewski, ?ukasz; Nowakowski, Andrzej; Gasik, Robert; ?ab?dŸ, Wojciech

    2013-01-01

    Background Degenerative disease of the lumbar spine is characterized by symptoms related to the affected nerve root. A recently described method allows the classification of the roots in relation to the occurrence of compression on its course. This method can serve as a clinical selection tool and decision support for semi-invasive pain therapy in back pain patients. Material/Methods We examined 40 lumbar spine MRIs in 3 sessions of transcription each, according to the method being evaluated. Every MRI evaluation was performed by each of 3 different observers. Intra- and interobserver reproducibility was calculated using chance-corrected agreement using a weighted kappa (?) value with quadratic weights to assess reliability for each nerve root separately. Results We found high intraobserver agreement in indication of the root with most pronounced interference due to potential compression by degenerative changes, at the level mean ?=0.81 (with 95% CI, range 0.04). Less agreement was observed in the interobserver evaluation test with the mean ?=0.75 (95% CI within the range not exceeding 0.03), although it still reached the substantial agreement. Conclusions This zstudy provides evidence for substantial inter- and intraobserver agreement for the decision support method allowing selection of the most serious nerve structure compression in degenerative disease of the lumbar spine based on of the MRI description. PMID:23524527

  13. Dorsal root ganglion-derived Schwann cells combined with poly(lactic-co-glycolic acid)/chitosan conduits for the repair of sciatic nerve defects in rats

    PubMed Central

    Zhao, Li; Qu, Wei; Wu, Yuxuan; Ma, Hao; Jiang, Huajun

    2014-01-01

    Schwann cells, nerve regeneration promoters in peripheral nerve tissue engineering, can be used to repair both the peripheral and central nervous systems. However, isolation and purification of Schwann cells are complicated by contamination with fibroblasts. Current reported measures are mainly limited by either high cost or complicated procedures with low cell yields or purity. In this study, we collected dorsal root ganglia from neonatal rats from which we obtained highly purified Schwann cells using serum-free melanocyte culture medium. The purity of Schwann cells (> 95%) using our method was higher than that using standard medium containing fetal bovine serum. The obtained Schwann cells were implanted into poly(lactic-co-glycolic acid)/chitosan conduits to repair 10-mm sciatic nerve defects in rats. Results showed that axonal diameter and area were significantly increased and motor functions were obviously improved in the rat sciatic nerve tissue. Experimental findings suggest that serum-free melanocyte culture medium is conducive to purify Schwann cells and poly(lactic-co-glycolic acid)/chitosan nerve conduits combined with Schwann cells contribute to restore sciatic nerve defects. PMID:25598778

  14. TREATMENT OUTCOMES OF INTRADISCAL STEROID INJECTION/SELECTIVE NERVE ROOT BLOCK FOR 161 PATIENTS WITH CERVICAL RADICULOPATHY

    PubMed Central

    ITO, KEIGO; YUKAWA, YASUTSUGU; MACHINO, MASAAKI; INOUE, TARO; OUCHIDA, JUN; TOMITA, KEISUKE; KATO, FUMIHIKO

    2015-01-01

    ABSTRACT Patients with cervical radiculopathy (CR) were treated with intradiscal injection of steroids (IDIS) and/or selective nerve root block (SNRB) at our hospital. We retrospectively report the outcomes of these nonsurgical treatments for CR. 161 patients who were followed up for >2months were enrolled in this study. Patients’ clinical manifestations were classified as arm pain, arm numbness, neck and/or scapular pain, and arm paralysis. Improvement in each manifestation was classified as "disappeared," "improved," "poor," or "worsened." Responses of "disappeared" or "improved" manifestations suggested treatment effectiveness. Final clinical outcomes were evaluated using the Odom criteria. Changes in herniated disc size were evaluated by comparing the initial and final MRI scans. On the basis of these changes, the patients were divided into regression, no-change, or progression groups. We investigated the relationship between the Odom criteria and changes observed on MRI. Effectiveness rates were 89% for arm pain, 77% for arm numbness, 82% for neck and/or scapular pain, and 76% for arm paralysis. In total, 91 patients underwent repeated MRI. In 56 patients (62%), the size of the herniated disc decreased, but 31 patients (34%) exhibited no change in disc size. The regression group showed significantly better Odom criteria results than the no-change group. In conclusion, IDIS and SNRB for CR are not widely performed. However, other extremely effective therapies that can rapidly improve neuralgia should be considered before surgery.

  15. Spinal cord herniation into pseudomeningocele after traumatic nerve root avulsion: case report and review of the literature

    PubMed Central

    Ikuma, Hisanori; Nakanishi, Kazuo; Sugimoto, Yoshihisa; Misawa, Haruo; Takigawa, Tomoaki; Ozaki, Toshifumi

    2007-01-01

    We present an extremely rare case of traumatic spinal cord herniation due to a brachial plexus avulsion injury and provide a review of the literature of spinal cord herniation. Spinal cord herniation is an uncommon condition that can occur spontaneously or as a result of surgery or trauma. This condition often presents with symptoms and signs as Brown-Séquard syndrome. Traumatic pseudomeningoceles after a brachial plexus avulsion injury have been reported. But transdural herniation of the spinal cord into this pseudomeningocele is an extremely rare and poorly documented condition. There is only two reports of this condition in a thoracic case. The authors report the case of a 22-year-old man presented with a 2-year history of quadriplegia. He was involved in a motorcycle accident, 3 years prior to his presentation. Four years after the initial right brachial plexus injury, he was not able to walk independently. Magnetic resonance imaging (MRI) and computerized tomography (CT) myelography revealed a lateral pseudomeningocele arising from the right C6–7 and C7–T1 intervetebral foramen and cervical spinal cord herniation into this pseudomeningocele. The patient underwent primary closure of pseudomeningocele to prevent spinal cord reherniation. He can walk with cane and use left arm unrestrictedly at the 2-year follow-up examination. Spinal cord herniation following traumatic nerve root avulsion is extremely rare but it should be considered in the differential diagnosis of patients presenting with delayed myelopathy or Brown-Séquard syndrome. PMID:17987326

  16. Successful operative management of an upper lumbar spinal canal stenosis resulting in multilevel lower nerve root radiculopathy

    PubMed Central

    McClelland, Shearwood; Kim, Stefan S.

    2015-01-01

    Lumbar stenosis is a common disorder, usually characterized clinically by neurogenic claudication with or without lumbar/sacral radiculopathy corresponding to the level of stenosis. We present a case of lumbar stenosis manifesting as a multilevel radiculopathy inferior to the nerve roots at the level of the stenosis. A 55-year-old gentleman presented with bilateral lower extremity pain with neurogenic claudication in an L5/S1 distribution (posterior thigh, calf, into the foot) concomitant with dorsiflexion and plantarflexion weakness. Imaging revealed grade I spondylolisthesis of L3 on L4 with severe spinal canal stenosis at L3-L4, mild left L4-L5 disc herniation, no stenosis at L5-S1, and no instability. EMG revealed active and chronic L5 and S1 radiculopathy. The patient underwent bilateral L3-L4 hemilaminotomy with left L4-L5 microdiscectomy for treatment of his L3-L4 stenosis. Postoperatively, he exhibited significant improvement in dorsiflexion and plantarflexion. The L5-S1 level was not involved in the operative decompression. Patients with radiculopathy and normal imaging at the level corresponding to the radiculopathy should not be ruled out for operative intervention should they have imaging evidence of lumbar stenosis superior to the expected affected level. PMID:25552866

  17. Pulsed Radiofrequency of the Dorsal Root Ganglia is Superior to Pharmacotherapy or Pulsed Radiofrequency of the Intercostal Nerves in the Treatment of Chronic Postsurgical Thoracic Pain

    Microsoft Academic Search

    Steven P. Cohen; Anthony Sireci; Christopher L. Wu; Thomas M. Larkin; Kayode A. Williams; Robert W. Hurley

    pulsed RF of the intercostal nerves (ICN) and pulsed RF of the dorsal root ganglia (DRG) in CPTP. Methods: Retrospective data analy- sis involving 49 patients. Results: At 6-week follow-up, 61.5% of the pulsed RF DRG group reported ? 50% pain relief vs. 27.3% in the medical management (MM) group and 21.4% in the ICN group (P=0.12). At 3-month follow-up,

  18. The organizational and activational effects of sex hormones on tactile and thermal hypersensitivity following lumbar nerve root injury in male and female rats

    PubMed Central

    LaCroix-Fralish, Michael L.; Tawfik, Vivianne L.; DeLeo, Joyce A.

    2005-01-01

    Considerable evidence exists for sex differences in human pain sensitivity. Women typically report a higher incidence of various painful conditions and report that the conditions are more painful when compared to men. In the present study, we sought to determine whether sex differences in pain sensitivity are observed using a lumbar radiculopathy model of low back pain in the rat and whether removal or alteration of gonadal hormones at specific timepoints can modulate these sex differences. Pubertal and adult male and female Sprague—Dawley rats were castrated 2 or 6 weeks prior to L5 nerve root injury to determine the activational hormonal effects. In a separate study, neonatal male and female Sprague—Dawley rats were either castrated or injected with testosterone, respectively, on postnatal day one to determine the organizational effects of gonadal hormones on L5 nerve root injury-induced behavioral hypersensitivity. Our results demonstrate that there was a statistically significant sex difference in the magnitude of mechanical allodynia and thermal hyperalgesia following experimentally induced radiculopathy in the rat: females demonstrated decreased thresholds to tactile and thermal stimuli as compared to males. Furthermore, the enhanced female hypersensitivity was reversed in pubertal and adult animals ovariectomized 6 weeks, but not 2 weeks prior to L5 nerve root injury. Our results demonstrate that the activational effects of gonadal hormones mediate the enhanced female tactile and thermal hypersensitivity following L5 nerve root injury. These results suggest that manipulation of gonadal hormones may be a potential source for novel therapies for chronic pain in women. PMID:15733633

  19. Differential Effects of Electrical Stimulation of Sciatic Nerve on Metabolic Activity in Spinal Cord and Dorsal Root Ganglion in the Rat

    Microsoft Academic Search

    Massako Kadekaro; Alison M. Crane; Louis Sokoloff

    1985-01-01

    Electrical stimulation of the proximal stump of the transected sciatic nerve produces a frequency-dependent activation of glucose utilization, measured with the autoradiographic deoxy[14C]glucose method, in the dorsal horn of the spinal cord but produces no change in glucose utilization in the dorsal root ganglion cells. These results suggest that axon terminals and not the cell bodies are the sites of

  20. Conus medulla-cauda compression from nerve root hypertrophy in a child with Dejerine-Sottas syndrome: improvement with laminectomy and duraplasty. Case report.

    PubMed

    Kleopa, Kleopas A; Sutton, Leslie N; Ong, Joseph; Tennekoon, Gihan; Telfeian, Albert E

    2002-09-01

    This 7-year-old boy with Dejerine-Sottas syndrome caused by a mutation in the myelin protein zero gene began to suffer rapid deterioration with increasing leg weakness, loss of the ability to ambulate, and bowel and bladder incontinence. Magnetic resonance imaging of the spine revealed nerve root hypertrophy resulting in compression of the conus medullaris and cauda equina. Decompressive surgery was successful in reversing some of his deficits. PMID:12296688

  1. Multi-scale simulations predict responses to non-invasive nerve root stimulation

    NASA Astrophysics Data System (ADS)

    Laakso, Ilkka; Matsumoto, Hideyuki; Hirata, Akimasa; Terao, Yasuo; Hanajima, Ritsuko; Ugawa, Yoshikazu

    2014-10-01

    Objective. Established biophysical neurone models have achieved limited success in reproducing electrophysiological responses to non-invasive stimulation of the human nervous system. This is related to our insufficient knowledge of the induced electric currents inside the human body. Despite the numerous research and clinical applications of non-invasive stimulation, it is still unclear which internal sites are actually affected by it. Approach. We performed multi-scale computer simulations that, by making use of advances in computing power and numerical algorithms, combine a microscopic model of electrical excitation of neurones with a macroscopic electromagnetic model of the realistic whole-body anatomy. Main results. The simulations yield responses consistent with those experimentally recorded following magnetic and electrical motor root stimulation in human subjects, and reproduce the observed amplitudes and latencies for a wide variety of stimulation parameters. Significance. Our findings demonstrate that modern computational techniques can produce detailed predictions about which and where neurones are activated, leading to improved understanding of the physics and basic mechanisms of non-invasive stimulation and enabling potential new applications that make use of improved targeting of stimulation.

  2. Selective decrease of small sensory neurons in lumbar dorsal root ganglia labeled with horseradish peroxidase after ND:YAG laser irradiation of the tibial nerve in the rat

    SciTech Connect

    Wesselmann, U.; Lin, S.F.; Rymer, W.Z. (Northwestern Univ. Medical School, Chicago, IL (USA))

    1991-02-01

    Recent electrophysiological evidence indicates that Q-switched Nd:YAG laser irradiation might have selective effects on neural impulse transmission in small slow conducting sensory nerve fibers as compared to large diameter afferents. In an attempt to clarify the ultimate fate of sensory neurons after laser application to their peripheral axons, we have used horseradish peroxidase (HRP) as a cell marker to retrogradely label sensory neurons innervating the distal hindlimb in the rat. Pulsed Nd:YAG laser light was applied to the tibial nerve at pulse energies of 70 or 80 mJ/pulse for 5 min in experimental rats. Seven days later HRP was applied to the left (laser-treated) and to the contralateral (untreated) tibial nerve proximal to the site of laser irradiation. In control animals the numbers of HRP-labeled dorsal root ganglion cells were not significantly different between the right and the left side. In contrast, after previous laser irradiation labeling was always less on the laser-treated side (2183 +/- 513 cells, mean +/- SEM) as compared to the untreated side (3937 +/- 225). Analysis of the dimensions of labeled cells suggested that the reduction of labeled cells on the laser-treated side was mainly due to a deficit in small sensory neurons. Since the conduction velocity of nerve fibers is related to the size of their somata, our histological data imply that laser light selectively affects retrograde transport mechanisms for HRP in slow conducting sensory nerve fibers.

  3. The Impact of Spinal Cord Nerve Roots and Denticulate Ligaments on Cerebrospinal Fluid Dynamics in the Cervical Spine

    PubMed Central

    Heidari Pahlavian, Soroush; Yiallourou, Theresia; Tubbs, R. Shane; Bunck, Alexander C.; Loth, Francis; Goodin, Mark; Raisee, Mehrdad; Martin, Bryn A.

    2014-01-01

    Cerebrospinal fluid (CSF) dynamics in the spinal subarachnoid space (SSS) have been thought to play an important pathophysiological role in syringomyelia, Chiari I malformation (CM), and a role in intrathecal drug delivery. Yet, the impact that fine anatomical structures, including nerve roots and denticulate ligaments (NRDL), have on SSS CSF dynamics is not clear. In the present study we assessed the impact of NRDL on CSF dynamics in the cervical SSS. The 3D geometry of the cervical SSS was reconstructed based on manual segmentation of MRI images of a healthy volunteer and a patient with CM. Idealized NRDL were designed and added to each of the geometries based on in vivo measurments in the literature and confirmation by a neuroanatomist. CFD simulations were performed for the healthy and patient case with and without NRDL included. Our results showed that the NRDL had an important impact on CSF dynamics in terms of velocity field and flow patterns. However, pressure distribution was not altered greatly although the NRDL cases required a larger pressure gradient to maintain the same flow. Also, the NRDL did not alter CSF dynamics to a great degree in the SSS from the foramen magnum to the C1 level for the healthy subject and CM patient with mild tonsillar herniation (?6 mm). Overall, the NRDL increased fluid mixing phenomena and resulted in a more complex flow field. Comparison of the streamlines of CSF flow revealed that the presence of NRDL lead to the formation of vortical structures and remarkably increased the local mixing of the CSF throughout the SSS. PMID:24710111

  4. Removal of a vertebral metastatic tumor compressing the spinal nerve roots via a single-port, transforaminal, endoscopic approach under monitored anesthesia care.

    PubMed

    Joo, Young-Chan; Ok, Whoi-Kyung; Baik, Seong-Hoon; Kim, Hae-Jin; Kwon, Oh-Sun; Kim, Kyung-Hoon

    2012-01-01

    Spinal cord or nerve root compression from an epidural metastasis occurs in 5-10% of patients with cancer and in up to 40% of patients with preexisting nonspinal bone metastases. Most metastatic spine diseases arise from the vertebral column, with the posterior half of the vertebral body being the most common initial focus, and/or the paravertebral region, tracking along the spinal nerves to enter the spinal column via the intervertebral foramina. An 82-year-old man diagnosed with sigmoid colon cancer and liver metastases experienced intractable pain described as being like an electric shock on the right T11 dermatome. Imaging studies revealed a huge metastatic mass destroying the right posterior T11 body and pedicle and compressing the right posterior spinal cord and nerve roots. Even after using neuropathic medication and a neural blockade, the extreme paroxysmal pain continued. Considering his elderly, debilitated state and life expectancy, removal of the vertebral metastatic tumor compressing the spinal nerve roots via a single-port, transforaminal, endoscopic approach and percutaneous vertebroplasty (PVP) under monitored anesthetic care (MAC), rather than 3-port endoscopic surgery and corpectomy with or without fusion under general anesthesia with lung deflation, was decided upon and scheduled prior to radiotherapy. A needle was placed into the intervertebral foramen under fluoroscopy in the same manner as a transforaminal epidural block at T11. A guidewire was inserted into the needle after the needle stylet had been removed. An obturator dilator was inserted over the guidewire, and a working sleeve was inserted over the dilator. After the dilator was removed, a spinal endoscope with a 2.7 mm working channel was placed over the guidewire. Careful removal of the tumor emboli during verbal interaction with the patient was performed under MAC using dexmedetomidine, fentanyl, and ketorolac. PVP at T11 was performed through the right osteolytic pedicle. The paroxysmal pain disappeared immediately after the operation without any complications. Removal of a vertebral metastatic tumor compressing the spinal nerve roots via a single-port, transforaminal, endoscopic approach under monitored anesthesia care without lung deflation may be an effective and safe modality for minimally invasive pain management of a single-level spinal tumor metastasis causing intractable radicular pain in patients with cancer who have generalized debilitation. PMID:22828683

  5. A temporal variation in nonneuronal protein synthesis in dorsal root ganglia and nerve and its significance to studies of axonal transport

    SciTech Connect

    Snyder, R.E.; O'Brien, D.W.; Nihei, T.

    1984-03-01

    Protein synthesis and fast axonal transport were studied in vitro using dorsal root ganglia (DRG)-sciatic nerve preparations from the amphibian Xenopus laevis. It was observed that the rate of incorporation of (/sup 3/H)leucine into protein in DRG and isolated segments of nerve began to increase 9 to 11 h after killing the animal, attaining at 13 to 17 h a maximum of 5- to 10-times preincrease (less than 9 h) values. At the same time as an increase in the rate of incorporation began, synthesis commenced in DRG and nerve exposed to cycloheximide (125 micrograms/ml). Whereas cycloheximide reduced fast axonal transport to 1 to 3% of control values in preparations maintained 20 to 24 h in vitro, cycloheximide reduced incorporation in DRG to only 80% of control values. N-terminal labeling studies showed that both the increased incorporation and cycloheximide-insensitive incorporation resulted from protein synthesis. Autoradiographic and incorporation studies indicated that nonneuronal cells situated in the ganglion capsule and perineural sheath of the nerve were responsible for both the increased incorporation and cycloheximide-insensitive synthesis. The findings have implications for the study of axonal transport.

  6. Dorsal Root Ganglia Neurons and Differentiated Adipose-derived Stem Cells: An In Vitro Co-culture Model to Study Peripheral Nerve Regeneration.

    PubMed

    de Luca, Alba C; Faroni, Alessandro; Reid, Adam J

    2015-01-01

    Dorsal root ganglia (DRG) neurons, located in the intervertebral foramina of the spinal column, can be used to create an in vitro system facilitating the study of nerve regeneration and myelination. The glial cells of the peripheral nervous system, Schwann cells (SC), are key facilitators of these processes; it is therefore crucial that the interactions of these cellular components are studied together. Direct contact between DRG neurons and glial cells provides additional stimuli sensed by specific membrane receptors, further improving the neuronal response. SC release growth factors and proteins in the culture medium, which enhance neuron survival and stimulate neurite sprouting and extension. However, SC require long proliferation time to be used for tissue engineering applications and the sacrifice of an healthy nerve for their sourcing. Adipose-derived stem cells (ASC) differentiated into SC phenotype are a valid alternative to SC for the set-up of a co-culture model with DRG neurons to study nerve regeneration. The present work presents a detailed and reproducible step-by-step protocol to harvest both DRG neurons and ASC from adult rats; to differentiate ASC towards a SC phenotype; and combines the two cell types in a direct co-culture system to investigate the interplay between neurons and SC in the peripheral nervous system. This tool has great potential in the optimization of tissue-engineered constructs for peripheral nerve repair. PMID:25742570

  7. Dorsal Root Ganglia Neurons and Differentiated Adipose-derived Stem Cells: An In Vitro Co-culture Model to Study Peripheral Nerve Regeneration

    PubMed Central

    de Luca, Alba C.; Faroni, Alessandro; Reid, Adam J.

    2015-01-01

    Dorsal root ganglia (DRG) neurons, located in the intervertebral foramina of the spinal column, can be used to create an in vitro system facilitating the study of nerve regeneration and myelination. The glial cells of the peripheral nervous system, Schwann cells (SC), are key facilitators of these processes; it is therefore crucial that the interactions of these cellular components are studied together. Direct contact between DRG neurons and glial cells provides additional stimuli sensed by specific membrane receptors, further improving the neuronal response. SC release growth factors and proteins in the culture medium, which enhance neuron survival and stimulate neurite sprouting and extension. However, SC require long proliferation time to be used for tissue engineering applications and the sacrifice of an healthy nerve for their sourcing. Adipose-derived stem cells (ASC) differentiated into SC phenotype are a valid alternative to SC for the set-up of a co-culture model with DRG neurons to study nerve regeneration. The present work presents a detailed and reproducible step-by-step protocol to harvest both DRG neurons and ASC from adult rats; to differentiate ASC towards a SC phenotype; and combines the two cell types in a direct co-culture system to investigate the interplay between neurons and SC in the peripheral nervous system. This tool has great potential in the optimization of tissue-engineered constructs for peripheral nerve repair. PMID:25742570

  8. Nerve injury induces a Gem-GTPase-dependent downregulation of P/Q-type Ca2+ channels contributing to neurite plasticity in dorsal root ganglion neurons.

    PubMed

    Scamps, Frédérique; Sangari, Sina; Bowerman, Melissa; Rousset, Mathieu; Bellis, Michel; Cens, Thierry; Charnet, Pierre

    2015-02-01

    Small RGK GTPases, Rad, Gem, Rem1, and Rem2, are potent inhibitors of high-voltage-activated (HVA) Ca(2+) channels expressed in heterologous expression systems. However, the role of this regulation has never been clearly demonstrated in the nervous system. Using transcriptional analysis, we show that peripheral nerve injury specifically upregulates Gem in mice dorsal root ganglia. Following nerve injury, protein expression was increased in ganglia and peripheral nerve, mostly under its phosphorylated form. This was confirmed in situ and in vitro in dorsal root ganglia sensory neurons. Knockdown of endogenous Gem, using specific small-interfering RNA (siRNA), increased the HVA Ca(2+) current only in the large-somatic-sized neurons. Combining pharmacological analysis of the HVA Ca(2+) currents together with Gem siRNA-transfection of larger sensory neurons, we demonstrate that only the P/Q-type Ca(2+) channels were enhanced. In vitro analysis of Gem affinity to various CaV?x-CaV2.x complexes and immunocytochemical studies of Gem and CaV? expression in sensory neurons suggest that the specific inhibition of the P/Q channels relies on both the regionalized upregulation of Gem and the higher sensitivity of the endogenous CaV2.1-CaV?4 pair in a subset of sensory neurons including the proprioceptors. Finally, pharmacological inhibition of P/Q-type Ca(2+) current reduces neurite branching of regenerating axotomized neurons. Taken together, the present results indicate that a Gem-dependent P/Q-type Ca(2+) current inhibition may contribute to general homeostatic mechanisms following a peripheral nerve injury. PMID:24809506

  9. Monitoring of immune cell response to B cell depletion therapy and nerve root injury using SPIO enhanced MRI

    NASA Astrophysics Data System (ADS)

    Thorek, Daniel L.

    2009-12-01

    Magnetic resonance (MR) is a robust platform for non-invasive, high-resolution anatomical imaging. However, MR imaging lacks the requisite sensitivity and contrast for imaging at the cellular level. This represents a clinical impediment to greater diagnostic accuracy. Recent advances have allowed for the in vivo visualization of populations and even of individual cells using superparamagnetic iron oxide (SPIO) MR contrast agents. These nanoparticles, commonly manifested as a core of a single iron oxide crystal or cluster of crystals coated in a biocompatible shell, function to shorten proton relaxation times. In MR imaging these constructs locally dephase protons, resulting in a decrease in signal (hypointensity) localized to the region of accumulation of SPIO. In the context of immune cell imaging, SPIO can provide insight into the cellular migration patterns, trafficking, temporal dynamics and progression of diseases and their related pathological states. Furthermore, by visualizing the presence and activity of immune cells, SPIO-enabled cellular imaging can help evaluate the efficacy of therapy in immune disorders. This thesis examines the production, modification and application of SPIO in a range of in vitro and in vivo immune-response-relevant cellular systems. The role of different nanoparticle characteristics including diameter, surface charge and concentration are investigated in the labeling of T cells in culture. Following optimization of SPIO loading conditions for lymphocytes, the effect these particles have on the activation of primary B cells are elucidated. B cells are tracked using a variety of modalities, with and without the application of B cell depleting therapy. This is to evaluate the efficacy of SPIO as in vivo marker for B cell distribution. Unmodified SPIO were applied to monitor macrophage infiltration in a transient nerve root compression model, with implications for neck pain diagnosis and treatment. Nanoparticle accumulation and MR hypointensity was correlated to the presence of activated macrophage at the site of injury. Taken together, the application of SPIO to study nanoparticle uptake in vitro and visualization of immune cells in vivo provide a basis for advanced study and diagnosis of diverse pathologies.

  10. Sensory deficits of a nerve root lesion can be objectively documented by somatosensory evoked potentials elicited by painful infrared laser stimulations: a case study.

    PubMed Central

    Lorenz, J; Hansen, H C; Kunze, K; Bromm, B

    1996-01-01

    Somatosensory evoked potentials (SEPs) in response to painful laser stimuli were measured in a patient with a unilateral sensory deficit due to radiculopathy at cervical levels C7 and C8. Laser evoked potentials (LEPs) were compared with SEPs using standard electrical stimulation of median and ulnar nerves at the wrist and mechanical stimulation of the fingertips by means of a mechanical stimulator. Early and late ulnar and median nerve SEPs were normal. Mechanical stimulation resulted in w shaped early SEPs from all five fingertips with some degree of abnormality at the fourth and fifth digits of the affected hand. Late LEPs were completely absent for stimulations at affected dermatomes and normal in the unaffected control dermatomes. The border between skin areas with normal or absent LEPs was very sharp and fitted the dermatomes of intact C6 and damaged C7 and C8 nerve roots. It is suggested that pain dermatomes are narrower than tactile dermatomes because thin fibres of the nociceptive system, activated by laser stimuli, probably do not overlap between adjacent spinal segments to the same extent as thick fibres of the mechanoreceptive system, activated by standard electrical or mechanical stimulation. Images PMID:8676136

  11. Electromechanical Nerve Stimulator

    NASA Technical Reports Server (NTRS)

    Tcheng, Ping; Supplee, Frank H., Jr.; Prass, Richard L.

    1993-01-01

    Nerve stimulator applies and/or measures precisely controlled force and/or displacement to nerve so response of nerve measured. Consists of three major components connected in tandem: miniature probe with spherical tip; transducer; and actuator. Probe applies force to nerve, transducer measures force and sends feedback signal to control circuitry, and actuator positions force transducer and probe. Separate box houses control circuits and panel. Operator uses panel to select operating mode and parameters. Stimulator used in research to characterize behavior of nerve under various conditions of temperature, anesthesia, ventilation, and prior damage to nerve. Also used clinically to assess damage to nerve from disease or accident and to monitor response of nerve during surgery.

  12. Root canal

    MedlinePLUS

    A root canal is a dental procedure to remove dead or dying nerve tissue and bacteria from inside a tooth. ... is removed with special tools called files. The canals (tiny pathways inside the tooth) are cleaned. Medicines ...

  13. Neuronal expression of the ubiquitin ligase Nedd4-2 in rat dorsal root ganglia: modulation in the spared nerve injury model of neuropathic pain.

    PubMed

    Cachemaille, M; Laedermann, C J; Pertin, M; Abriel, H; Gosselin, R-D; Decosterd, I

    2012-12-27

    Neuronal hyperexcitability following peripheral nerve lesions may stem from altered activity of voltage-gated sodium channels (VGSCs), which gives rise to allodynia or hyperalgesia. In vitro, the ubiquitin ligase Nedd4-2 is a negative regulator of VGSC ?-subunits (Na(v)), in particular Na(v)1.7, a key actor in nociceptor excitability. We therefore studied Nedd4-2 in rat nociceptors, its co-expression with Na(v)1.7 and Na(v)1.8, and its regulation in pathology. Adult rats were submitted to the spared nerve injury (SNI) model of neuropathic pain or injected with complete Freund's adjuvant (CFA), a model of inflammatory pain. L4 dorsal root ganglia (DRG) were analyzed in sham-operated animals, seven days after SNI and 48 h after CFA with immunofluorescence and Western blot. We observed Nedd4-2 expression in almost 50% of DRG neurons, mostly small and medium-sized. A preponderant localization is found in the non-peptidergic sub-population. Additionally, 55.7 ± 2.7% and 55.0 ± 3.6% of Nedd4-2-positive cells are co-labeled with Na(v)1.7 and Na(v)1.8 respectively. SNI significantly decreases the proportion of Nedd4-2-positive neurons from 45.9 ± 1.9% to 33.5 ± 0.7% (p<0.01) and the total Nedd4-2 protein to 44% ± 0.13% of its basal level (p<0.01, n=4 animals in each group, mean ± SEM). In contrast, no change in Nedd4-2 was found after peripheral inflammation induced by CFA. These results indicate that Nedd4-2 is present in nociceptive neurons, is downregulated after peripheral nerve injury, and might therefore contribute to the dysregulation of Na(v)s involved in the hyperexcitability associated with peripheral nerve injuries. PMID:23022218

  14. Low Frequency Electroacupuncture Alleviated Spinal Nerve Ligation Induced Mechanical Allodynia by Inhibiting TRPV1 Upregulation in Ipsilateral Undamaged Dorsal Root Ganglia in Rats

    PubMed Central

    Fang, Jian-Qiao

    2013-01-01

    Neuropathic pain is an intractable problem in clinical practice. Accumulating evidence shows that electroacupuncture (EA) with low frequency can effectively relieve neuropathic pain. Transient receptor potential vanilloid type 1 (TRPV1) plays a key role in neuropathic pain. The study aimed to investigate whether neuropathic pain relieved by EA administration correlates with TRPV1 inhibition. Neuropathic pain was induced by right L5 spinal nerve ligation (SNL) in rats. 2?Hz?EA stimulation was administered. SNL induced mechanical allodynia in ipsilateral hind paw. SNL caused a significant reduction of TRPV1 expression in ipsilateral L5 dorsal root ganglia (DRG), but a significant up-regulation in ipsilateral L4 and L6 DRGs. Calcitonin gene-related peptide (CGRP) change was consistent with that of TRPV1. EA alleviated mechanical allodynia, and inhibited TRPV1 and CGRP overexpressions in ipsilateral L4 and L6 DRGs. SNL did not decrease pain threshold of contralateral hind paw, and TRPV1 expression was not changed in contralateral L5 DRG. 0.001, 0.01?mg/kg TRPV1 agonist 6?-IRTX fully blocked EA analgesia in ipsilateral hind paw. 0.01?mg/kg 6?-IRTX also significantly decreased pain threshold of contralateral paw. These results indicated that inhibition of TRPV1 up-regulation in ipsilateral adjacent undamaged DRGs contributed to low frequency EA analgesia for mechanical allodynia induced by spinal nerve ligation. PMID:23935654

  15. Expression of the vesicular glutamate transporters-1 and -2 in adult mouse dorsal root ganglia and spinal cord and their regulation by nerve injury.

    PubMed

    Brumovsky, P; Watanabe, M; Hökfelt, T

    2007-06-29

    The expression of two vesicular glutamate transporters (VGLUTs), VGLUT1 and VGLUT2, was studied with immunohistochemistry in lumbar dorsal root ganglia (DRGs), the lumbar spinal cord and the skin of the adult mouse. About 12% and 65% of the total number of DRG neuron profiles (NPs) expressed VGLUT1 and VGLUT2, respectively. VGLUT1-immunoreactive (IR) NPs were usually medium- to large-sized, in contrast to a majority of small- or medium-sized VGLUT2-IR NPs. Most VGLUT1-IR NPs did not coexpress calcitonin gene-related peptide (CGRP) or bound isolectin B4 (IB4). In contrast, approximately 31% and approximately 42% of the VGLUT2-IR DRG NPs were also CGRP-IR or bound IB4, respectively. Conversely, virtually all CGRP-IR and IB4-binding NPs coexpressed VGLUT2. Moderate colocalization between VGLUT1 and VGLUT2 was also observed. Sciatic nerve transection induced a decrease in the overall number of VGLUT1- and VGLUT2-IR NPs (both ipsi- and contralaterally) and, in addition, a parallel, unilateral increase of VGLUT2-like immunoreactivity (LI) in a subpopulation of mostly small NPs. In the dorsal horn of the spinal cord, strong VGLUT1-LI was detected, particularly in deep dorsal horn layers and in the ventral horns. VGLUT2-LI was abundant throughout the gray spinal matter, 'radiating' into/from the white matter. A unilateral dorsal rhizotomy reduced VGLUT1-LI, while apparently leaving unaffected the VGLUT2-LI. Transport through axons for both VGLUTs was confirmed by their accumulation after compression of the sciatic nerve or dorsal roots. In the hind paw skin, abundant VGLUT2-IR nerve fibers were observed, sometimes associated with Merkel cells. Lower numbers of VGLUT1-IR fibers were also detected in the skin. Some VGLUT1-IR and VGLUT2-IR fibers were associated with hair follicles. Based on these data and those by Morris et al. [Morris JL, Konig P, Shimizu T, Jobling P, Gibbins IL (2005) Most peptide-containing sensory neurons lack proteins for exocytotic release and vesicular transport of glutamate. J Comp Neurol 483:1-16], we speculate that virtually all DRG neurons in adult mouse express VGLUTs and use glutamate as transmitter. PMID:17577523

  16. Vascularization of the dorsal root ganglia and peripheral nerve of the mouse: Implications for chemical-induced peripheral sensory neuropathies

    Microsoft Academic Search

    Juan M Jimenez-Andrade; Monica B Herrera; Joseph R Ghilardi; Marina Vardanyan; Ohannes K Melemedjian; Patrick W Mantyh

    2008-01-01

    Although a variety of industrial chemicals, as well as several chemotherapeutic agents used to treat cancer or HIV, preferentially induce a peripheral sensory neuropathy what remains unclear is why these agents induce a sensory vs. a motor or mixed neuropathy. Previous studies have shown that the endothelial cells that vascularize the dorsal root ganglion (DRG), which houses the primary afferent

  17. Genetic variability in the rat Aplec C-type lectin gene cluster regulates lymphocyte trafficking and motor neuron survival after traumatic nerve root injury

    PubMed Central

    2013-01-01

    Background C-type lectin (CLEC) receptors are important for initiating and shaping immune responses; however, their role in inflammatory reactions in the central nervous system after traumatic injuries is not known. The antigen-presenting lectin-like receptor gene complex (Aplec) contains a few CLEC genes, which differ genetically among inbred rat strains. It was originally thought to be a region that regulates susceptibility to autoimmune arthritis, autoimmune neuroinflammation and infection. Methods The inbred rat strains DA and PVG differ substantially in degree of spinal cord motor neuron death following ventral root avulsion (VRA), which is a reproducible model of localized nerve root injury. A large F2 (DAxPVG) intercross was bred and genotyped after which global expressional profiling was performed on spinal cords from F2 rats subjected to VRA. A congenic strain, Aplec, created by transferring a small PVG segment containing only seven genes, all C-type lectins, ontoDA background, was used for further experiments together with the parental strains. Results Global expressional profiling of F2 (DAxPVG) spinal cords after VRA and genome-wide eQTL mapping identified a strong cis-regulated difference in the expression of Clec4a3 (Dcir3), a C-type lectin gene that is a part of the Aplec cluster. Second, we demonstrate significantly improved motor neuron survival and also increased T-cell infiltration into the spinal cord of congenic rats carrying Aplec from PVG on DA background compared to the parental DA strain. In vitro studies demonstrate that the Aplec genes are expressed on microglia and upregulated upon inflammatory stimuli. However, there were no differences in expression of general microglial activation markers between Aplec and parental DA rats, suggesting that the Aplec genes are involved in the signaling events rather than the primary activation of microglia occurring upon nerve root injury. Conclusions In summary, we demonstrate that a genetic variation in Aplec occurring among inbred strains regulates both survival of axotomized motor neurons and the degree of lymphocyte infiltration. These results demonstrate a hitherto unknown role for CLECs for intercellular communication that occurs after damage to the nervous system, which is relevant for neuronal survival. PMID:23656637

  18. Effects of sciatic nerve transection on glucose uptake in the presence and absence of lactate in the frog dorsal root ganglia and spinal cord.

    PubMed

    Rigon, F; Horst, A; Kucharski, L C; Silva, R S M; Faccioni-Heuser, M C; Partata, W A

    2014-08-01

    Frogs have been used as an alternative model to study pain mechanisms because the simplicity of their nervous tissue and the phylogenetic aspect of this question. One of these models is the sciatic nerve transection (SNT), which mimics the clinical symptoms of "phantom limb", a condition that arises in humans after amputation or transverse spinal lesions. In mammals, the SNT increases glucose metabolism in the central nervous system, and the lactate generated appears to serve as an energy source for nerve cells. An answerable question is whether there is elevated glucose uptake in the dorsal root ganglia (DRG) after peripheral axotomy. As glucose is the major energy substrate for frog nervous tissue, and these animals accumulate lactic acid under some conditions, bullfrogs Lithobates catesbeianus were used to demonstrate the effect of SNT on DRG and spinal cord 1-[14C] 2-deoxy-D-glucose (14C-2-DG) uptake in the presence and absence of lactate. We also investigated the effect of this condition on the formation of 14CO2 from 14C-glucose and 14C-L-lactate, and plasmatic glucose and lactate levels. The 3-O-[14C] methyl-D-glucose (14C-3-OMG) uptake was used to demonstrate the steady-state tissue/medium glucose distribution ratio under these conditions. Three days after SNT, 14C-2-DG uptake increased, but 14C-3-OMG uptake remained steady. The increase in 14C-2-DG uptake was lower when lactate was added to the incubation medium. No change was found in glucose and lactate oxidation after SNT, but lactate and glucose levels in the blood were reduced. Thus, our results showed that SNT increased the glucose metabolism in the frog DRG and spinal cord. The effect of lactate on this uptake suggests that glucose is used in glycolytic pathways after SNT. PMID:25627385

  19. Extracellular Nm23H1 stimulates neurite outgrowth from dorsal root ganglia neurons in vitro independently of nerve growth factor supplementation or its nucleoside diphosphate kinase activity

    SciTech Connect

    Wright, K.T. [Keele University at the RJAH Orthopaedic Hospital, Oswestry, Shropshire (United Kingdom)] [Keele University at the RJAH Orthopaedic Hospital, Oswestry, Shropshire (United Kingdom); Seabright, R.; Logan, A. [Neuropharmacology and Neurobiology, School of Clinical and Experimental Medicine, Birmingham University, Birmingham (United Kingdom)] [Neuropharmacology and Neurobiology, School of Clinical and Experimental Medicine, Birmingham University, Birmingham (United Kingdom); Lilly, A.J.; Khanim, F.; Bunce, C.M. [Biosciences, Birmingham University, Birmingham (United Kingdom)] [Biosciences, Birmingham University, Birmingham (United Kingdom); Johnson, W.E.B., E-mail: w.e.johnson@aston.ac.uk [Life and Health Sciences, Aston University, Birmingham (United Kingdom)] [Life and Health Sciences, Aston University, Birmingham (United Kingdom)

    2010-07-16

    Research highlights: {yields} Extracellular Nm23H1 stimulates nerve growth. {yields} Extracellular Nm23H1 provides pathfinding cues to growth cones. {yields} The neurotrophic activity of Nm23H1 is independent of NDP kinase activity. {yields} The neurotrophic activity of Nm23H1 is independent of NGF. -- Abstract: The nucleoside diphosphate (NDP) kinase, Nm23H1, is a highly expressed during neuronal development, whilst induced over-expression in neuronal cells results in increased neurite outgrowth. Extracellular Nm23H1 affects the survival, proliferation and differentiation of non-neuronal cells. Therefore, this study has examined whether extracellular Nm23H1 regulates nerve growth. We have immobilised recombinant Nm23H1 proteins to defined locations of culture plates, which were then seeded with explants of embryonic chick dorsal root ganglia (DRG) or dissociated adult rat DRG neurons. The substratum-bound extracellular Nm23H1 was stimulatory for neurite outgrowth from chick DRG explants in a concentration-dependent manner. On high concentrations of Nm23H1, chick DRG neurite outgrowth was extensive and effectively limited to the location of the Nm23H1, i.e. neuronal growth cones turned away from adjacent collagen-coated substrata. Nm23H1-coated substrata also significantly enhanced rat DRG neuronal cell adhesion and neurite outgrowth in comparison to collagen-coated substrata. These effects were independent of NGF supplementation. Recombinant Nm23H1 (H118F), which does not possess NDP kinase activity, exhibited the same activity as the wild-type protein. Hence, a novel neuro-stimulatory activity for extracellular Nm23H1 has been identified in vitro, which may function in developing neuronal systems.

  20. Techniques of peripheral nerve repair.

    PubMed

    Dahlin, L B

    2008-01-01

    Nerve injuries extend from simple nerve compression lesions to complete nerve injuries and severe lacerations of the nerve trunks. A specific problem is brachial plexus injuries where nerve roots can be ruptured, or even avulsed from the spinal cord, by traction. An early and correct diagnosis of a nerve injury is important. A thorough knowledge of the anatomy of the peripheral nerve trunk as well as of basic neurobiological alterations in neurons and Schwann cells induced by the injury are crucial for the surgeon in making adequate decisions on how to repair and reconstruct nerves. The technique of peripheral nerve repair includes four important steps (preparation of nerve end, approximation, coaptation and maintenance). Nerves are usually repaired primarily with sutures applied in the different tissue components, but various tubes are available. Nerve grafts and nerve transfers are alternatives when the injury induces a nerve defect. Timing of nerve repair is essential. An early repair is preferable since it is advantageous for neurobiological reasons. Postoperative rehabilitation, utilising the patients' own coping strategies, with evaluation of outcome are additional important steps in treatment of peripheral nerve injuries. in the rehabilitation phase adequate handling of pain, allodynia and cold intolerance are emphasised. PMID:19211385

  1. Subtype-specific reduction of Voltage-gated Calcium Current in Medium-Sized Dorsal Root Ganglion Neurons after Painful Peripheral Nerve Injury

    PubMed Central

    McCallum, J. Bruce; Wu, Hsiang-En; Tang, Qingbo; Kwok, Wai-Meng; Hogan, Quinn H.

    2011-01-01

    Sensory neurons express a variety of voltage-gated Ca2+ channel subtypes, but reports differ on their proportionate representation, and the effects of painful nerve injury on each subtype are not established. We compared levels of high-voltage activated currents in medium-sized (30-40?m) dorsal root ganglion neurons dissociated from control animals and those subjected to spinal nerve ligation, using sequential application of semiselective channel blockers (nisoldipine for L-type, SNX-111 or ?-conotoxin GVIA for N-type, agatoxin IVA or ?-Conotoxin MVIIC for P/Q-type, and SNX-482 for a component of R-type) during either square wave depolarizations or action potential waveform voltage commands. Using sequential administration of multiple blockers, proportions of total Ca2+ current attributable to different subtypes and the effect of injury depended on the sequence of blocker administration and type of depolarization command. Overall, however, N-type and L-type currents comprised the dominant components of ICa in sensory neurons under control conditions, and these subtypes showed the greatest loss of current following injury (L-type 26-71% loss, N-type 0-51% loss). Further exploration of N-type current identified by its sensitivity to ?-conotoxin GVIA applied alone showed that injury reduced the peak N-type current during step depolarization by 68% and decreased the total charge entry during action potential waveform stimulation by 44%. Isolation of N-type current by blockade of all other subtypes demonstrated a 50% loss with injury, and also revealed an injury-related rightward shift in the activation curve. Nonstationary noise analyses of N-type current in injured neurons revealed unitary channel current and number of channels that were not different from control, which indicates that injury-induced loss of current is due to a decrease in channel open probability. Our findings suggest that diminished Ca2+ influx through N-type and L-type channels may contribute to sensory neuron dysfunction and pain after nerve injury. PMID:21277351

  2. [The effect of hormones on the rate of axonal transport in the ventral spinal nerve roots of rats].

    PubMed

    Frol'kis, V V; Tanin, S A; Martsinko, V I

    1990-01-01

    The Wistar male rats in the age of 8-12 months were injected 7-8 microliter of aqueous solution of L-leucine-14C (specific activity 12543 megaBq/mmol) into the area of the ventral horn at the level of L5,6 segment of the spinal cord. The study of radioactivity in various sections of the respective frontal root was performed after one hour. It was found that estradiol dipropionate, testosterone propionate, insulin and small doses of thyroxin increased the axonal transport of the labelled material, while hydrocortisone, large doses of thyroxin, castration and thyroidectomy caused its delay. It is concluded that the axonal transport is under a pronounced hormonal control. PMID:1704487

  3. De novo expression of Nav1.7 in injured putative proprioceptive afferents: Multiple tetrodotoxin-sensitive sodium channels are retained in the rat dorsal root after spinal nerve ligation.

    PubMed

    Fukuoka, T; Miyoshi, K; Noguchi, K

    2015-01-22

    Tetrodotoxin-sensitive (TTX-s) spontaneous activity is recorded from the dorsal roots after peripheral nerve injury. Primary sensory neurons in the dorsal root ganglion (DRG) express multiple TTX-s voltage-gated sodium channel ?-subunits (Navs). Since Nav1.3 increases, whereas all other Navs decrease, in the DRG neurons after peripheral nerve lesion, Nav1.3 is proposed to be critical for the generation of these spontaneous discharges and the contributions of other Navs have been ignored. Here, we re-evaluate the changes in expression of three other TTX-s Navs, Nav1.1, Nav1.6 and Nav1.7, in the injured 5th lumbar (L5) primary afferent components following L5 spinal nerve ligation (SNL) using in situ hybridization histochemistry and immunohistochemistry. While the overall signal intensities for these Nav mRNAs decreased, many injured DRG neurons still expressed these transcripts at clearly detectable levels. All these Nav proteins accumulated at the proximal stump of the ligated L5 spinal nerve. The immunostaining patterns of Nav1.6 and Nav1.7 associated with the nodes of Ranvier were maintained in the ipsilateral L5 dorsal root. Interestingly, putative proprioceptive neurons characterized by ?3 Na+/K+ ATPase-immunostaining specifically lacked Nav1.7 mRNA in naïve DRG but displayed de novo expression of this transcript following SNL. Nav1.7-immunoreactive fibers were significantly increased in the ipsilateral gracile nucleus where central axonal branches of the injured A-fiber afferents terminated. These data indicate that multiple TTX-s channel subunits could contribute to the generation and propagation of the spontaneous discharges in the injured primary afferents. Specifically, Nav1.7 may cause some functional changes in sensory processing in the gracile nucleus after peripheral nerve injury. PMID:25453779

  4. Evaluation of Behavior and Expression of Receptor Activator of Nuclear Factor-Kappa B Ligand in Dorsal Root Ganglia after Sciatic Nerve Compression and Application of Nucleus Pulposus in Rats

    PubMed Central

    Matsuyama, Yoshiyuki; Sakuma, Yoshihiro; Suzuki, Miyako; Orita, Sumihisa; Yamauchi, Kazuyo; Inoue, Gen; Aoki, Yasuchika; Ishikawa, Tetsuhiro; Miyagi, Masayuki; Kamoda, Hiroto; Kubota, Gou; Oikawa, Yasuhiro; Inage, Kazuhide; Sainoh, Takeshi; Sato, Jun; Nakamura, Junichi; Toyone, Tomoaki; Takahashi, Kazuhisa

    2014-01-01

    Study Design Experimental animal study. Purpose To evaluate pain-related behavior and changes in nuclear factor-kappa B (NF-kB), receptor activator of NF-kB (RANK), and ligand (RANKL) in dorsal root ganglia (DRG) after combined sciatic nerve compression and nucleus pulposus (NP) application in rats. Overview of Literature The pathological mechanisms underlying pain from lumbar-disc herniation have not been fully elucidated. RANKL are transcriptional regulators of inflammatory cytokines. Our aim was to evaluate pain-related behavior and RANKL expression in DRG after sciatic-nerve compression and application of NP in rats. Methods Mechanical hyperalgesia and RANKL expression were assessed in three groups of rats: NP+sciatic nerve compression (2 seconds), sham-operated, and controls (n=20 each). Mechanical hyperalgesia was measured every other day for 3 weeks using von Frey filaments. RANKL expression in L5 DRGs was examined at five and ten days after surgery using immunohistochemistry. Results Mechanical hyperalgesia was observed over the 12-day observation period in the NP+nerve compression group, but not in the control and sham-operated animal groups (p<0.05). RANKL immunoreactivity was seen in the nuclei of L5 DRG neurons, and its expression was significantly upregulated in NP+nerve compression rats compared with control and sham-operated rats (p<0.01). Conclusions The exposure of sciatic nerves to mechanical compression and NP produces pain-related behavior and up-regulation of RANKL in DRG neurons. RANKL may play an important role in mediating pain after sciatic nerve injury with exposure to NP. PMID:25346807

  5. mTOR and its downstream pathway are activated in the dorsal root ganglion and spinal cord after peripheral inflammation, but not after nerve injury.

    PubMed

    Liang, Lingli; Tao, Bo; Fan, Longchang; Yaster, Myron; Zhang, Yi; Tao, Yuan-Xiang

    2013-06-01

    Protein translation controlled through activation of mammalian target of rapamycin (mTOR) participates in many physiological and pathological processes. However, whether such activation is required for chronic pain is still unknown. Here, we examined activation of the mTOR signaling pathway during complete Freund's adjuvant (CFA)-induced chronic inflammatory pain and L5 spinal nerve ligation (SNL)-induced neuropathic pain in rats. Western blot analysis showed significantly increased levels of phosphorylated mTOR (p-mTOR) and phosphorylated p70S6 kinase 1 (p-S6K1, a downstream effector of mTOR) in the ipsilateral L4/5 spinal cord 2h, 1 day, 3 days, and 7 days after intraplantar CFA injection and in the ipsilateral L4/5 dorsal root ganglions (DRGs) 1 and 3 days after CFA injection. Immunohistochemistry also demonstrated increases in number of p-mTOR-labeled neurons in the ipsilateral L4/5 DRGs and in density of p-mTOR-labeled immunoreactivity in the ipsilateral L4/5 superficial dorsal horn 1 day after CFA injection. Moreover, intrathecal administration of rapamycin, a selective inhibitor of mTOR, significantly blocked CFA-induced mechanical allodynia and thermal hyperalgesia 1 day post-CFA injection. Interestingly, expression of neither p-mTOR nor p-S6K1 was markedly altered on days 3, 7, or 14 after L5 SNL in L5 spinal cord or DRG. These findings indicate that in DRG and spinal cord, mTOR and S6K1 are activated during chronic inflammatory pain, but not during neuropathic pain. Our results strongly suggest that mTOR and its downstream pathway contribute to the development of chronic inflammatory pain. PMID:23583278

  6. An Evaluation of the Effectiveness of Hyaluronidase in the Selective Nerve Root Block of Radiculopathy: A Double Blind, Controlled Clinical Trial

    PubMed Central

    Ko, Sang-Bong; Vaccaro, Alexander R; Shin, Dong-Young

    2015-01-01

    Study Design Prospective, double-blind, randomized controlled trial. Purpose To determine the ability of hyaluronidase to provide longer lasting pain relief and functional improvement in patients with lumbar radiculopathy. Overview of Literature Selective nerve root block (SNRB) is a good treatment option in lumbar radiculopathy. We studied the effectiveness of hyaluronidase when added to the traditional SNRB regimen. Methods A sample size of 126 patients per group was necessary. A sample of 252 patients who underwent an injection procedure with or without hyaluronidase due to radiculopathy was included in this study. The patients were randomly divided into two groups: the control (C) group and the hyaluronidase (H) group. After SNRB due to radiculopathy, the visual analog scale (VAS) was compared at 2, 4, 6, 8, and 12 weeks between the two groups, and the Oswestry disability index (ODI) was compared at 12 weeks between the two groups. Results Both groups seemed to have general improvement in VAS, but in C group, the VAS was higher than the H group 2 and 4 weeks after the surgery, and the difference in time-group change between 2 groups was statistically significant (p <0.05). ODI improved in both groups, and the difference in time-group change between 2 groups was not statistically significant (p >0.05). Conclusions The rebound pain (the re-occurrence of pain within 2-4 weeks after injection) that occurs within 2-4 weeks after the injection of the routine regimen can be reduced when hyaluronidase is added to the routine SNRB regimen. PMID:25705339

  7. Effects of sciatic nerve transection on ultrastructure, NADPH-diaphorase reaction and serotonin-, tyrosine hydroxylase-, c-Fos-, glucose transporter 1- and 3-like immunoreactivities in frog dorsal root ganglion.

    PubMed

    Rigon, F; Rossato, D; Auler, V B; Dal Bosco, L; Faccioni-Heuser, M C; Partata, W A

    2013-06-01

    Frogs have been used as an alternative model to study pain mechanisms. Since we did not find any reports on the effects of sciatic nerve transection (SNT) on the ultrastructure and pattern of metabolic substances in frog dorsal root ganglion (DRG) cells, in the present study, 18 adult male frogs (Rana catesbeiana) were divided into three experimental groups: naive (frogs not subjected to surgical manipulation), sham (frogs in which all surgical procedures to expose the sciatic nerve were used except transection of the nerve), and SNT (frogs in which the sciatic nerve was exposed and transected). After 3 days, the bilateral DRG of the sciatic nerve was collected and used for transmission electron microscopy. Immunohistochemistry was used to detect reactivity for glucose transporter (Glut) types 1 and 3, tyrosine hydroxylase, serotonin and c-Fos, as well as nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-diaphorase). SNT induced more mitochondria with vacuolation in neurons, satellite glial cells (SGCs) with more cytoplasmic extensions emerging from cell bodies, as well as more ribosomes, rough endoplasmic reticulum, intermediate filaments and mitochondria. c-Fos immunoreactivity was found in neuronal nuclei. More neurons and SGCs surrounded by tyrosine hydroxylase-like immunoreactivity were found. No change occurred in serotonin- and Glut1- and Glut3-like immunoreactivity. NADPH-diaphorase occurred in more neurons and SGCs. No sign of SGC proliferation was observed. Since the changes of frog DRG in response to nerve injury are similar to those of mammals, frogs should be a valid experimental model for the study of the effects of SNT, a condition that still has many unanswered questions. PMID:23739744

  8. Notch Root Biaxial Cyclic Strain Behavior of Type 304 Stainless Steel at Elevated Temperature Using Laser Speckle Strain/Displacement Gauge

    NASA Astrophysics Data System (ADS)

    Waki, Hiroyuki; Ogura, Keiji; Nishikawa, Izuru

    A laser speckle biaxial strain gauge was developed to measure local strains, ?y, ?z, at notch roots. Measurements were made on single edge-notched type 304 stainless specimens under fully reversed cyclic loading at both 673 K and room temperature. The strain ranges, ??y, ??z, and a ratio of those, ?=??z/??y, were discussed in terms of a proposed notch root deformation constraint parameter which consisted of a notch root radius, a thickness of the plate and a nominal stress level. It was found that the biaxial strain ratio, ?, was uniquely correlated with the proposed parameter for all the tested notches. It was also found that no change in the notch root strain range during the whole fatigue life was observed for the limited condition in which the constraint parameter took a sufficiently large value. Furthermore, the verification of Neuber’s rule in terms of the measured strain was discussed.

  9. A new model of traumatic axonal injury to determine the effects of strain and displacement rates.

    PubMed

    Singh, Anita; Lu, Ying; Chen, Chaoyang; Kallakuri, Srinivasu; Cavanaugh, John M

    2006-11-01

    Traumatic brain injury (TBI) continues to be a major health problem, with over 500,000 cases per year with a societal cost of approximately $85 billion in the US. Motor vehicle accidents are the leading cause of such injuries. In many cases of TBI widespread disruption of the axons occurs through a process known as diffuse axonal injury (DAI) or traumatic axonal injury (TAI). In the current study, an in vivo TAI model was developed using spinal nerve roots of adult rats. This model was used to determine functional and structural responses of axons to various strains and displacement rates. Fifty-six L5 dorsal nerve roots were each subjected to a predetermined strain range (<10%, 10-20% and >20%) at a specified displacement rate (0.01 mm/sec and 15 mm/sec) only once. Image analysis was used to determine actual strains on the roots during the pull. Neurophysiologic recordings were performed on the nerve root before and after stretch to determine functional changes in response to stretch, including conduction velocity (CV) and area of the evoked compound action potential (CAP). Structural changes including vascular injury, axotomy, and impaired axoplasmic transport (IAT) were evaluated using hematoxylin and eosin, Palmgren silver impregnation and beta-APP staining techniques, respectively. Results showed that CV and the area of the CAP decreased as strain and displacement rate increased. Also, threshold strains for complete nerve conduction loss were 16% and 9% at 0.01 mm/sec and 15 mm/sec rate, respectively. These threshold values indicate the rate dependency of functional injury and indicate that axons tolerate slow loading rates better than higher loading rates. Histological studies revealed increased spacing, tearing of axons, IAT and occurrence of hemorrhage to be strain and displacement rate dependent. Linear relationships existed between the increasing strain and the occurrence rate of axonal injury as evidenced by multiple indicators (IAT, hemorrhage, torn fibers or primary axotomy) at both rates. In conclusion, the results from this study indicate that the severity of both functional and structural injury increased with increases in strain and displacement rate. PMID:17311179

  10. Phrenic nerve transfer to the musculocutaneous nerve for the repair of brachial plexus injury: electrophysiological characteristics

    PubMed Central

    Liu, Ying; Xu, Xun-cheng; Zou, Yi; Li, Su-rong; Zhang, Bin; Wang, Yue

    2015-01-01

    Phrenic nerve transfer is a major dynamic treatment used to repair brachial plexus root avulsion. We analyzed 72 relevant articles on phrenic nerve transfer to repair injured brachial plexus that were indexed by Science Citation Index. The keywords searched were brachial plexus injury, phrenic nerve, repair, surgery, protection, nerve transfer, and nerve graft. In addition, we performed neurophysiological analysis of the preoperative condition and prognosis of 10 patients undergoing ipsilateral phrenic nerve transfer to the musculocutaneous nerve in our hospital from 2008 to 201 3 and observed the electromyograms of the biceps brachii and motor conduction function of the musculocutaneous nerve. Clinically, approximately 28% of patients had brachial plexus injury combined with phrenic nerve injury, and injured phrenic nerve cannot be used as a nerve graft. After phrenic nerve transfer to the musculocutaneous nerve, the regenerated potentials first appeared at 3 months. Recovery of motor unit action potential occurred 6 months later and became more apparent at 12 months. The percent of patients recovering ‘excellent’ and ‘good’ muscle strength in the biceps brachii was 80% after 18 months. At 12 months after surgery, motor nerve conduction potential appeared in the musculocutaneous nerve in seven cases. These data suggest that preoperative evaluation of phrenic nerve function may help identify the most appropriate nerve graft in patients with an injured brachial plexus. The functional recovery of a transplanted nerve can be dynamically observed after the surgery.

  11. Differential regulation of immune responses and macrophage\\/neuron interactions in the dorsal root ganglion in young and adult rats following nerve injury

    Microsoft Academic Search

    David Vega-Avelaira; Sandrine M Géranton; Maria Fitzgerald

    2009-01-01

    BACKGROUND: Neuropathic pain is an apparently spontaneous experience triggered by abnormal physiology of the peripheral or central nervous system, which evolves with time. Neuropathic pain arising from peripheral nerve injury is characterized by a combination of spontaneous pain, hyperalgesia and allodynia. There is no evidence of this type of pain in human infants or rat pups; brachial plexus avulsion, which

  12. Expression of c-Fos and c-Jun in adjacent cervical spinal cord segments following C7 nerve root rhizotomy in rats: Indication of a neural pathway between adjacent cervical spinal cord segments

    PubMed Central

    LI, HUI; LI, QING; XIE, KELIANG; FENG, SHIQING; WANG, PEI; MA, XINLONG

    2013-01-01

    Cervical radiculopathy is a common disease in clinical practice. However, the symptoms are not confined to the affected spinal cord segment indicated by magnetic resonance imaging (MRI) findings. In the present study, we measured c-Fos and c-Jun expression in ipsilateral and adjacent cervical spinal cord segments following C7 nerve root rhizotomy, to determine whether there is a neural pathway between adjacent cervical spinal cord segments. Forty-eight adult male Wistar rats were randomly divided into two groups: the C7 rhizotomy group (rhizotomy group, n=24) and the sham-operated group (sham group, n=24). The right C7 nerve root was completely cut off in the rhizotomy group, while it was exposed but not cut in the sham group. The expression of c-Fos and c-Jun in cervical spinal cord segments was detected by immunohistochemistry at 2 and 4 h after surgery. We observed that the number of c-Fos- and c-Jun-positive neurons in ipsilateral C5–7 segments were significantly increased at 2 and 4 h after C7 nerve root rhizotomy (P<0.05 vs. the sham group). The location of c-Fosand c-Jun-positive neurons in C5–7 gray matter was similar in the rhizotomy and sham groups, which was mainly in lamina IX of the anterior horn and laminae I–II of the dorsal horn of the spinal cord. However, the number of c-Fos- and c-Jun-positive neurons in the C5–7 gray matter was significantly reduced at 4 h after surgery compared with the number 2 h after surgery. The location of c-Fos- and c-Jun-positive neurons at 4 h was similar with that at 2 h. Therefore, there may be a neural pathway between ipsilateral adjacent cervical spinal cord segments. This may be one possible explanation as to why the radicular symptoms of cervical radiculopathy are not confined to the affected spinal cord segment shown by MRI. PMID:24137191

  13. Cranial Nerves IX, X, XI, and XII

    PubMed Central

    Sanders, Richard D.

    2010-01-01

    This article concludes the series on cranial nerves, with review of the final four (IX–XII). To summarize briefly, the most important and common syndrome caused by a disorder of the glossopharyngeal nerve (craniel nerve IX) is glossopharyngeal neuralgia. Also, swallowing function occasionally is compromised in a rare but disabling form of tardive dyskinesia called tardive dystonia, because the upper motor portion of the glossopharyngel nerve projects to the basal ganglia and can be affected by lesions in the basal ganglia. Vagus nerve funtion (craniel nerve X) can be compromised in schizophrenia, bulimia, obesity, and major depression. A cervical lesion to the nerve roots of the spinal accessory nerve (craniel nerve XI) can cause a cervical dystonia, which sometimes is misdiagnosed as a dyskinesia related to neuroleptic use. Finally, unilateral hypoglossal (craniel nerve XII) nerve palsy is one of the most common mononeuropathies caused by brain metastases. Supranuclear lesions of cranial nerve XII are involved in pseudobulbar palsy and ALS, and lower motor neuron lesions of cranial nerve XII can also be present in bulbar palsy and in ALS patients who also have lower motor neuron involvement. This article reviews these and other syndromes related to cranial nerves IX through XII that might be seen by psychiatry. PMID:20532157

  14. Protein expression of sensory and motor nerves

    PubMed Central

    Ren, Zhiwu; Wang, Yu; Peng, Jiang; Zhang, Li; Xu, Wenjing; Liang, Xiangdang; Zhao, Qing; Lu, Shibi

    2012-01-01

    The present study utilized samples from bilateral motor branches of the femoral nerve, as well as saphenous nerves, ventral roots, and dorsal roots of the spinal cord, to detect differential protein expression using two-dimensional gel electrophoresis and nano ultra-high performance liquid chromatography electrospray ionization mass spectrometry tandem mass spectrometry techniques. A mass spectrum was identified using the Mascot search. Results revealed differential expression of 11 proteins, including transgelin, Ig kappa chain precursor, plasma glutathione peroxidase precursor, an unnamed protein product (gi|55628), glyceraldehyde-3-phosphate dehydrogenase-like protein, lactoylglutathione lyase, adenylate kinase isozyme 1, two unnamed proteins products (gi|55628 and gi|1334163), and poly(rC)-binding protein 1 in motor and sensory nerves. Results suggested that these proteins played roles in specific nerve regeneration following peripheral nerve injury and served as specific markers for motor and sensory nerves.

  15. Xenografted fetal dorsal root ganglion, embryonic stem cell and adult neural stem cell survival following implantation into the adult vestibulocochlear nerve

    Microsoft Academic Search

    C. Regala; M. Duan; J. Zou; M. Salminen; P. Olivius

    2005-01-01

    Sensorineural hearing loss is a disabling condition. In the post-embryonic and adult mammalian inner ear, the regeneration of auditory hair cells, spiral ganglion neurons or their axons does not occur naturally. This decrease in excitable neurons limits the success of auditory rehabilitation.Allografts and xenografts have shown promise in the treatment of a variety of neurological diseases. Fetal dorsal root ganglion

  16. Displaced Supersymmetry

    E-print Network

    Peter W. Graham; David E. Kaplan; Surjeet Rajendran; Prashant Saraswat

    2012-04-26

    The apparent absence of light superpartners at the LHC strongly constrains the viability of the MSSM as a solution to the hierarchy problem. These constraints can be significantly alleviated by R-parity violation (RPV). Bilinear R-parity violation, with the single operator L H_u, does not require any special flavor structure and can be naturally embedded in a GUT while avoiding constraints from proton decay (unlike baryon-number-violating RPV). The LSP in this scenario can be naturally long-lived, giving rise to displaced vertices. Many collider searches, particularly those selecting b-jets or leptons, are insensitive to events with such detector-scale displaced decays owing to cuts on track quality and impact parameter. We demonstrate that for decay lengths in the window ~1-1000 mm, constraints on superpartner masses can be as low as ~450 GeV for squarks and ~40 GeV for LSPs. In some parts of parameter space light LSPs can dominate the Higgs decay width, hiding the Higgs from existing searches. This framework motivates collider searches for detector-scale displaced vertices. LHCb may be ideally suited to trigger on such events, while ATLAS and CMS may need to trigger on missing energy in the event.

  17. Clinical nerve conduction and needle electromyography studies.

    PubMed

    Lee, Donald H; Claussen, Gwendolyn C; Oh, Shin

    2004-01-01

    The electrodiagnostic study, consisting of nerve conduction studies and needle electromyography, is a useful adjunct to the clinical examination of the peripheral nervous system. The three types of nerve conduction study are motor, sensory, and mixed, of which motor is the least sensitive. Electromyography records the intrinsic electrical activity of muscle fibers, thus providing the physiologic status of muscle function. To interpret the electrodiagnostic study results, the clinician must understand the anatomic and physiologic basis of the studies. Peripheral nerve entrapment initially results in focal demyelination; thus, nerve conduction velocity slows across the site. However, with radiculopathy and nerve root compression, the nerve conduction study may be normal. Both nerve trauma and polyneuropathy show marked differences in their effect on the results of electrodiagnostic studies. PMID:15473679

  18. Expression of the vesicular glutamate transporters-1 and -2 in adult mouse dorsal root ganglia and spinal cord and their regulation by nerve injury

    Microsoft Academic Search

    P. Brumovsky; M. Watanabe; T. Hökfelt

    2007-01-01

    The expression of two vesicular glutamate transporters (VGLUTs), VGLUT1 and VGLUT2, was studied with immunohistochemistry in lumbar dorsal root ganglia (DRGs), the lumbar spinal cord and the skin of the adult mouse. About 12% and 65% of the total number of DRG neuron profiles (NPs) expressed VGLUT1 and VGLUT2, respectively. VGLUT1-immunoreactive (IR) NPs were usually medium- to large-sized, in contrast

  19. Nerve Blocks

    MedlinePLUS

    ... doctor. By performing a nerve block and then monitoring how the patient responds to the injection, the ... and/or imaging guidance. He or she will clean the area with antiseptic solution, and then the ...

  20. Different patterns of nerve enlargement in polyneuropathy subtypes as detected by ultrasonography.

    PubMed

    Scheidl, Erika; Böhm, Josef; Simó, Magdolna; Bereznai, Benjamin; Bereczki, Dániel; Arányi, Zsuzsanna

    2014-06-01

    The purpose of our study was to examine how the pathologic type of polyneuropathy affects nerve size as assessed by high-resolution ultrasonography with a 15 MHz transducer. Cross-sectional area (CSA) of the C5-C7 nerve roots and several upper and lower limb nerves at multiple sites was measured in 38 patients with acquired diffuse sensorimotor demyelinating or axonal polyneuropathy and in 34 healthy control subjects. Significant differences were found among the groups for all nerve and root segments: Both types of polyneuropathy are characterized by nerve enlargement in comparison to controls, but in different patterns. In demyelinating polyneuropathies, an additional degree of nerve thickening appears in proximal upper limb nerves and cervical nerve roots compared with axonal polyneuropathies. With respect to the other nerves, a similar degree of nerve enlargement was observed in both patient groups. These results highlight that ultrasonography may be a complementary tool in differentiating polyneuropathies. PMID:24613217

  1. Chronic inflammatory demyelinating polyradiculoneuropathy with diffuse and massive peripheral nerve hypertrophy: distinctive clinical and magnetic resonance imaging features.

    PubMed

    Mizuno, K; Nagamatsu, M; Hattori, N; Yamamoto, M; Goto, H; Kuniyoshi, K; Sobue, G

    1998-06-01

    We present 3 patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) with extensive and diffuse hypertrophy of the nerve roots and peripheral nerves. They exhibited slowly progressive sensory impairment and distally predominant limb weakness and muscular atrophy, and markedly enlarged palpable nerve trunks. They responded beneficially to corticosteroid. Magnetic resonance imaging demonstrated diffuse and extensive hypertrophy of the peripheral nerves in the four limbs and the spinal nerve roots, with gadolinium enhancement in the nerve roots but not in the peripheral nerves. These patients were considered to have a hypertrophic variant of CIDP. PMID:9585338

  2. Bladder reinnervation using a primarily motor donor nerve (femoral nerve branches) is functionally superior to using a primarily sensory donor nerve (genitofemoral nerve)

    PubMed Central

    Gomez-Amaya, Sandra M.; Barbe, Mary F.; Brown, Justin M.; Lamarre, Neil S.; Braverman, Alan S.; Massicotte, Vicky S.; Ruggieri, Michael R.

    2014-01-01

    Purpose To determine whether transfer of a primarily motor nerve (Femoral, F) to the anterior vesicle branch of the pelvic nerve (PN) allows more effective bladder reinnervation than a primarily sensory nerve (genitofemoral, GF). Methods Forty-one female mongrel hounds underwent bladder decentralization, decentralization and then bilateral nerve transfer (GFNT and FNT) or were sham/unoperated controls. Decentralization was achieved by bilateral transection of all sacral roots that induce bladder contractions upon electrical stimulation. The retrograde neuronal labeling dye fluorogold was injected into the bladder 3 weeks prior to euthanasia. Results Increased detrusor pressure after direct stimulation of the transferred nerve, lumbar spinal cord or spinal roots was observed in 12/17 GFNT dogs (mean detrusor pressure = 7.6±1.4 cmH2O) and in 9/10 FNT-V dogs (mean detrusor pressure = 11.7±3.1 cm H2O). The mean detrusor pressures after direct electrical stimulation of transferred femoral nerves were statistically significantly greater than after stimulation of the transferred genitofemoral nerves. Retrogradely labeled neurons from the bladder observed in upper lumbar cord segments after GFNT and FNT confirmed bladder reinnervation as did labeled axons at the nerve transfer site. Conclusions While transfer of either a mixed sensory and motor nerve (GFN) or a primarily motor nerve (FN) can reinnervate the bladder, using a primarily motor nerve provides greater return of nerve-evoked detrusor contraction. This surgical approach may be useful for patients with lower motor spinal cord injury to accomplish bladder emptying. PMID:25066874

  3. Peripheral Nerve Disorders

    MedlinePLUS

    ... spinal cord. Like static on a telephone line, peripheral nerve disorders distort or interrupt the messages between the brain ... body. There are more than 100 kinds of peripheral nerve disorders. They can affect one nerve or many nerves. ...

  4. Transitional Nerve: A New and Original Classification of a Peripheral Nerve Supported by the Nature of the Accessory Nerve (CN XI).

    PubMed

    Benninger, Brion; McNeil, Jonathan

    2010-01-01

    Classically, the accessory nerve is described as having a cranial and a spinal root. Textbooks are inconsistent with regard to the modality of the spinal root of the accessory nerve. Some authors report the spinal root as general somatic efferent (GSE), while others list a special visceral efferent (SVE) modality. We investigated the comparative, anatomical, embryological, and molecular literature to determine which modality of the accessory nerve was accurate and why a discrepancy exists. We traced the origin of the incongruity to the writings of early comparative anatomists who believed the accessory nerve was either branchial or somatic depending on the origin of its target musculature. Both theories were supported entirely by empirical observations of anatomical and embryological dissections. We find ample evidence including very recent molecular experiments to show the cranial and spinal root are separate entities. Furthermore, we determined the modality of the spinal root is neither GSE or SVE, but a unique peripheral nerve with a distinct modality. We propose a new classification of the accessory nerve as a transitional nerve, which demonstrates characteristics of both spinal and cranial nerves. PMID:21318044

  5. Transitional Nerve: A New and Original Classification of a Peripheral Nerve Supported by the Nature of the Accessory Nerve (CN XI)

    PubMed Central

    Benninger, Brion; McNeil, Jonathan

    2010-01-01

    Classically, the accessory nerve is described as having a cranial and a spinal root. Textbooks are inconsistent with regard to the modality of the spinal root of the accessory nerve. Some authors report the spinal root as general somatic efferent (GSE), while others list a special visceral efferent (SVE) modality. We investigated the comparative, anatomical, embryological, and molecular literature to determine which modality of the accessory nerve was accurate and why a discrepancy exists. We traced the origin of the incongruity to the writings of early comparative anatomists who believed the accessory nerve was either branchial or somatic depending on the origin of its target musculature. Both theories were supported entirely by empirical observations of anatomical and embryological dissections. We find ample evidence including very recent molecular experiments to show the cranial and spinal root are separate entities. Furthermore, we determined the modality of the spinal root is neither GSE or SVE, but a unique peripheral nerve with a distinct modality. We propose a new classification of the accessory nerve as a transitional nerve, which demonstrates characteristics of both spinal and cranial nerves. PMID:21318044

  6. Nanofibrous nerve conduit-enhanced peripheral nerve regeneration.

    PubMed

    Jiang, Xu; Mi, Ruifa; Hoke, Ahmet; Chew, Sing Yian

    2014-05-01

    Fibre structures represent a potential class of materials for the formation of synthetic nerve conduits due to their biomimicking architecture. Although the advantages of fibres in enhancing nerve regeneration have been demonstrated, in vivo evaluation of fibre size effect on nerve regeneration remains limited. In this study, we analyzed the effects of fibre diameter of electrospun conduits on peripheral nerve regeneration across a 15-mm critical defect gap in a rat sciatic nerve injury model. By using an electrospinning technique, fibrous conduits comprised of aligned electrospun poly (?-caprolactone) (PCL) microfibers (981?±?83 nm, Microfiber) or nanofibers (251?±?32 nm, Nanofiber) were obtained. At three months post implantation, axons regenerated across the defect gap in all animals that received fibrous conduits. In contrast, complete nerve regeneration was not observed in the control group that received empty, non-porous PCL film conduits (Film). Nanofiber conduits resulted in significantly higher total number of myelinated axons and thicker myelin sheaths compared to Microfiber and Film conduits. Retrograde labeling revealed a significant increase in number of regenerated dorsal root ganglion sensory neurons in the presence of Nanofiber conduits (1.93 ± 0.71 × 10(3) vs. 0.98 ± 0.30 × 10(3) in Microfiber, p?nerve regeneration. These results could provide useful insights for future nerve guide designs. PMID:22700359

  7. Nerve Racking

    NSDL National Science Digital Library

    Integrated Teaching and Learning Program,

    This lesson describes the function and components of the human nervous system. It helps students understand the purpose of our brain, spinal cord, nerves and the five senses. How the nervous system is affected during spaceflight is also discussed in this lesson.

  8. Lateral displacement and rotational displacement sensor

    DOEpatents

    Duden, Thomas

    2014-04-22

    A position measuring sensor formed from opposing sets of capacitor plates measures both rotational displacement and lateral displacement from the changes in capacitances as overlapping areas of capacitors change. Capacitances are measured by a measuring circuit. The measured capacitances are provided to a calculating circuit that performs calculations to obtain angular and lateral displacement from the capacitances measured by the measuring circuit.

  9. Massive peripheral nerve hypertrophy in a patient with chronic inflammatory demyelinating polyradiculoneuropathy.

    PubMed

    Albini Riccioli, L; D'Agostino, V; Marliani, A F; Leonardi, M

    2008-02-18

    We describe a male patient with chronic inflammatory demyelinating polyradiculoneuropathy presenting extensive diffuse hypertrophy of the nerve roots of peripheral nerves. Since adolescence the patient has had a slow and progressive mainly distal loss of sensitivity and muscle weakness in all four limbs. He presented with diffuse muscle atrophy with enlarged palpable nerve trunks. Electromyography disclosed impaired sensory and motor responses in the bilateral median nerves and the right ulnar nerve. CSF examination showed elevated protein content, while MR scans depicted extensive hypertrophy of the spinal nerve roots. The patient benefitted from corticosteroid treatment. PMID:24256758

  10. Computer Simulation of Antidromic Facial Nerve Response Waveform

    Microsoft Academic Search

    Mitsuru Iwai; Taizo Takeda; Hiroaki Nakatani; Akinobu Kakigi

    2009-01-01

    Conclusion: An assessment of facial nerve (FN) damage on the basis of antidromic facial nerve response (AFNR) was established by computer simulation analysis. Computer simulation has the advantage of being able to assume any type of lesion. In the near future, computer analysis should provide another experimental method which displaces animal experiments, thus circumventing the ethical dilemma associated with animal

  11. Ulnar nerve injury following midshaft forearm fractures in children

    Microsoft Academic Search

    S. Stahl; N. Rozen; M. Michaelson

    1997-01-01

    We report three cases of ulnar nerve deficit in children following closed fractures of the forearm bones. Significant anterior angulation and displacement of the ulna was noted in all patients. Two patients were operated on at a later stage when no evidence of recovery was demonstrated; the ulnar nerve was found to be embedded in dense scar tissue. One patient

  12. Intermediate nerve neuralgia can be diagnosed and cured by microvascular decompression.

    PubMed

    Chen, Yili; Song, Zhengfei; Wan, Yingfeng; Lin, Wei; Hu, Xingyue; Wang, Yirong; Imai, Hideaki

    2014-07-01

    Here, we present a case of a 55-year-old woman with a 10-year history of hemifacial spasm accompanied by 1-month ipsilateral paroxysmal otalgia. Magnetic resonance imaging revealed the presence of vessels around the facial nerve root. Surgical exploration via suboccipital retromastoid craniotomy showed converging compression of the facial nerve root and intermediate nerve from both sides by an anterior inferior cerebellar artery loop. The patient's hemifacial spasm and ipsilateral otalgia were completely relieved after microvascular decompression of the facial nerve root and intermediate nerve. Intraoperative findings and the postoperative result of this case confirmed that vascular compression of the intermediate nerve was the exclusive cause of paroxysmal otalgia. The presence of ipsilateral hemifacial spasm, combined with preoperative neuroimaging studies, contributed to the diagnosis of intermediate nerve neuralgia. Microvascular decompression should be considered for the management of patients with intermediate nerve neuralgia. PMID:25006894

  13. Sacral Root Stimulation for Controlled Defecation

    Microsoft Academic Search

    A. Shafik

    1995-01-01

    Selective rectal or sphincter neurostimulation aiming at controlled defecation was performed in 10 dogs. While the dogs were under anesthesia, the rectal and rectal neck pressures, balloon expulsion as well as external anal sphincter (EAS) response to stimulation of the second sacral ventral nerve root (S2) and its autonomic and somatic branches were determined. Each of these nerves was stimulated

  14. Nerve Impulses in Plants

    ERIC Educational Resources Information Center

    Blatt, F. J.

    1974-01-01

    Summarizes research done on the resting and action potential of nerve impulses, electrical excitation of nerve cells, electrical properties of Nitella, and temperature effects on action potential. (GS)

  15. Collagen nerve wrap for median nerve scarring.

    PubMed

    Kokkalis, Zinon T; Mavrogenis, Andreas F; Ballas, Efstathios G; Papagelopoulos, Panayiotis J; Soucacos, Panayotis N

    2015-02-01

    Nerve wrapping materials have been manufactured to inhibit nerve tissue adhesions and diminish inflammatory and immunologic reactions in nerve surgery. Collagen nerve wrap is a biodegradable type I collagen material that acts as an interface between the nerve and the surrounding tissues. Its main advantage is that it stays in place during the period of tissue healing and is then gradually absorbed once tissue healing is completed. This article presents a surgical technique that used a collagen nerve wrap for the management of median nerve tissue adhesions in 2 patients with advanced carpal tunnel syndrome due to median nerve scarring and adhesions. At last follow-up, both patients had complete resolution with no recurrence of their symptoms. Complications related to the biodegradable material were not observed. PMID:25665110

  16. Electrophysiologicalproperties were monitored in detail in chronically con-stricted peripheral nerves by implanted, multicontact nerve cuff electrodes

    E-print Network

    Loeb, Gerald E.

    similar but less pronounced changes than larger diameter fibers. Recordings from ventral and dorsal roots * "dying-back'' degeneration * secondary demyelination MUSCLE & NERVE 12~915-928 1989 CONDUCTION STUDIES in peripheral nerve fiber caliber occur as a consequence of traumatic lesions. Retrograde atrophy of mature

  17. Let-7 microRNAs Regenerate Peripheral Nerve Regeneration by Targeting Nerve Growth Factor

    PubMed Central

    Li, Shiying; Wang, Xinghui; Gu, Yun; Chen, Chu; Wang, Yaxian; Liu, Jie; Hu, Wen; Yu, Bin; Wang, Yongjun; Ding, Fei; Liu, Yan; Gu, Xiaosong

    2015-01-01

    Peripheral nerve injury is a common clinical problem. Nerve growth factor (NGF) promotes peripheral nerve regeneration, but its clinical applications are limited by several constraints. In this study, we found that the time-dependent expression profiles of eight let-7 family members in the injured nerve after sciatic nerve injury were roughly similar to each other. Let-7 microRNAs (miRNAs) significantly reduced cell proliferation and migration of primary Schwann cells (SCs) by directly targeting NGF and suppressing its protein translation. Following sciatic nerve injury, the temporal change in let-7 miRNA expression was negatively correlated with that in NGF expression. Inhibition of let-7 miRNAs increased NGF secretion by primary cultured SCs and enhanced axonal outgrowth from a coculture of primary SCs and dorsal root gangalion neurons. In vivo tests indicated that let-7 inhibition promoted SCs migration and axon outgrowth within a regenerative microenvironment. In addition, the inhibitory effect of let-7 miRNAs on SCs apoptosis might serve as an early stress response to nerve injury, but this effect seemed to be not mediated through a NGF-dependent pathway. Collectively, our results provide a new insight into let-7 miRNA regulation of peripheral nerve regeneration and suggest a potential therapy for repair of peripheral nerve injury. PMID:25394845

  18. Diffuse spinal and intercostal nerve involvement in chronic inflammatory demyelinating polyradiculoneuropathy: MRI findings.

    PubMed

    Oguz, Berna; Oguz, Kader Karli; Cila, Aysenur; Tan, Ersin

    2003-12-01

    Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an uncommon demyelinating disorder with a relapsing and remitting or continuously progressive course. Hypertrophic nerve roots, sometimes associated with gadolinium enhancement, has been reported more commonly in lumbar spine and less commonly in the brachial plexus and cervical roots; however, diffuse involvement of intercostal nerves bilaterally has never been reported previously. We present MRI findings which include diffuse enlargement and mild enhancement of roots and extraforaminal segments of nerves in all segments except a short segment between T12-L2 as well as all the intercostal nerves in a case of CIPD with a 10-year history. PMID:15018192

  19. Diffuse spinal and intercostal nerve involvement in chronic inflammatory demyelinating polyradiculoneuropathy: MRI findings.

    PubMed

    Oguz, Berna; Oguz, Kader Karli; Cila, Aysenur; Tan, Ersin

    2003-12-01

    Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an uncommon demyelinating disorder with a relapsing and remitting or continuously progressive course. Hypertrophic nerve roots, sometimes associated with gadolinium enhancement, has been reported more commonly in lumbar spine and less commonly in the brachial plexus and cervical roots; however, diffuse involvement of intercostal nerves bilaterally has never been reported previously. We present MRI findings which include diffuse enlargement and mild enhancement of roots and extraforaminal segments of nerves in all segments except a short segment between T12-L2 as well as all the intercostal nerves in a case of CIPD with a 10-year history. PMID:16440223

  20. Diffuse spinal and intercostal nerve involvement in chronic inflammatory demyelinating polyradiculoneuropathy: MRI findings

    Microsoft Academic Search

    Berna Oguz; Kader Karli Oguz; Aysenur Cila; Ersin Tan

    2003-01-01

    Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an uncommon demyelinating disorder with a relapsing and remitting or continuously progressive course. Hypertrophic nerve roots, sometimes associated with gadolinium enhancement, has been reported more commonly in lumbar spine and less commonly in the brachial plexus and cervical roots; however, diffuse involvement of intercostal nerves bilaterally has never been reported previously. We present MRI

  1. Resting and Action Potentials of Reversed Polarity in Frog Nerve Cells

    Microsoft Academic Search

    I. Tasaki

    1959-01-01

    THE present communication deals with the resting and action potentials of the nerve cell body of the frog dorsal root ganglion immersed in barium-rich media. Dorsal root ganglia were removed from the ventral side of the vertebræ of a Rana pipiens together with nerves 5-10 mm. long on both sides. The preparation was immersed in a sodium free solution containing

  2. Regenerative scaffold electrodes for peripheral nerve interfacing.

    PubMed

    Clements, Isaac P; Mukhatyar, Vivek J; Srinivasan, Akhil; Bentley, John T; Andreasen, Dinal S; Bellamkonda, Ravi V

    2013-07-01

    Advances in neural interfacing technology are required to enable natural, thought-driven control of a prosthetic limb. Here, we describe a regenerative electrode design in which a polymer-based thin-film electrode array is integrated within a thin-film sheet of aligned nanofibers, such that axons regenerating from a transected peripheral nerve are topographically guided across the electrode recording sites. Cultures of dorsal root ganglia were used to explore design parameters leading to cellular migration and neurite extension across the nanofiber/electrode array boundary. Regenerative scaffold electrodes (RSEs) were subsequently fabricated and implanted across rat tibial nerve gaps to evaluate device recording capabilities and influence on nerve regeneration. In 20 of these animals, regeneration was compared between a conventional nerve gap model and an amputation model. Characteristic shaping of regenerated nerve morphology around the embedded electrode array was observed in both groups, and regenerated axon profile counts were similar at the eight week end point. Implanted RSEs recorded evoked neural activity in all of these cases, and also in separate implantations lasting up to five months. These results demonstrate that nanofiber-based topographic cues within a regenerative electrode can influence nerve regeneration, to the potential benefit of a peripheral nerve interface suitable for limb amputees. PMID:23033438

  3. High Displacement Actuator (HDA)

    NASA Technical Reports Server (NTRS)

    1994-01-01

    Positioned beneath a fiber optic displacement sensor is the new High Displacement Actuator (HDA) developed by scientists at NASA Langley Research Center. The high displacement actuator significantly improves the state-of-the-art piezoelectric technology and provides inordinately large mechanical displacements. The HDA is also applicable to high performance sensor applications such as microphones, non-destructive testing, and vibration sensing. Test results on the high displacement actuators show displacements 50 times greater than device thickness and several orders of magnitude increase over state-of-the-art devices. The actuators can be used from DC to frequencies in excess of a megahertz and with displacement loads exceeding 10 Kg (25 lbs). The actuator can also produce displacements comparable to state-of-the-art devices with an order reduction in operating voltage. The high displacement actuators are reliable. They have been laboratory tested to beyond 400 million cycles without failure. The highly efficient electrically- insulated actuator can be operated in a vacuum, in liquids, and in the upper atmosphere. The HDA is versatile and rugged allowing for use in harsh environments for hundreds of commercial applications. In many device applications the high displacement actuator wafer itself can serve the function of several components, e.g. in simple pumps it take the place of piston, piston-rod and crank. The HDA is a packaged flexible laminate of pre-stressed polymeric materials and a piezoelectric ceramic that form a robust, low cost, user friendly device.

  4. Root systems

    NSDL National Science Digital Library

    N/A N/A (U.S. Government; )

    2004-10-30

    One purpose that roots serve is that of anchoring the plant in the ground. Roots also take up water and nutrients for the plant. Plants all have different root system types to fit their individual needs and locations.

  5. Precision displacement reference system

    DOEpatents

    Bieg, Lothar F. (Albuquerque, NM); Dubois, Robert R. (Albuquerque, NM); Strother, Jerry D. (Edgewood, NM)

    2000-02-22

    A precision displacement reference system is described, which enables real time accountability over the applied displacement feedback system to precision machine tools, positioning mechanisms, motion devices, and related operations. As independent measurements of tool location is taken by a displacement feedback system, a rotating reference disk compares feedback counts with performed motion. These measurements are compared to characterize and analyze real time mechanical and control performance during operation.

  6. Nerve conduction velocity

    MedlinePLUS

    ... to determine the speed of the nerve signals. Electromyography (recording from needles placed into the muscles) is ... Often, the nerve conduction test is followed by electromyography (EMG). In this test, needles are placed into ...

  7. Ulnar nerve damage (image)

    MedlinePLUS

    ... elbow because of elbow fracture or dislocation. The ulnar nerve is near the surface of the body where it crosses the elbow, so prolonged pressure on the elbow or entrapment of the nerve may cause damage. Damage to ...

  8. Distal median nerve dysfunction

    MedlinePLUS

    ... is necessary to look for an underlying medical problem that can affect nerves. Medical conditions such as diabetes and kidney disease can damage nerves. In these cases, treatment is directed at the underlying medical condition. Physical ...

  9. Nerve Injuries in Athletes.

    ERIC Educational Resources Information Center

    Collins, Kathryn; And Others

    1988-01-01

    Over a two-year period this study evaluated the condition of 65 athletes with nerve injuries. These injuries represent the spectrum of nerve injuries likely to be encountered in sports medicine clinics. (Author/MT)

  10. Cranial Nerves Model

    NSDL National Science Digital Library

    Juliann Garza (University of Texas-Pan American Physician Assistant Studies)

    2010-08-16

    Lesson is designed to introduce students to cranial nerves through the use of an introductory lecture. Students will then create a three-dimensional model of the cranial nerves. An information sheet will accompany the model in order to help students learn crucial aspects of the cranial nerves.

  11. [X-ray computed tomography of lumbosacral roots and primary hypertrophic neuritis (Dejerine-Sottas disease)].

    PubMed

    Mas, J L; Buthiau, D; Fallet-Bianco, C; Cheron, F; Raulo, P; de Recondo, J; Rondot, P

    1989-01-01

    CT without contrast of lumbosacral nerve roots was performed in 13 patients with peroneal atrophy and 28 control subjects. Two series of 5 mm serial sections parallel to the plane of the disk were examined at the L4-L5 and L5-S1 levels, and the transverse diameter of the S1 nerve roots measured at the lower part of the lateral recess. Results showed frank bilateral, grossly symmetrical hypertrophy of lumbosacral roots in 8 of the 13 patients. This hypertrophy involved all roots examined (L4, L5, S1), except in one case where only S1 roots were involved. Hypertrophy was often more marked on the distal part of the roots and on spinal nerves, contrasting with the sometimes normal or only slightly altered appearance of the nerve roots emerging from the dural sac. In these 8 cases, the diameter of the S1 nerve roots was 8 to 18 mm, in contrast to a mean of 3.5 +/- 1 mm in the 28 controls. CT scan images were normal in the remaining 5 patients. The presence of a CT image of nerve hypertrophy was in all cases associated with a marked fall in nerve conduction rate (median nerve motor conduction rate less than 25 msec-1), and a decrease in number of myelinated fibers with numerous onion bulbs. In contrast, the absence of CT nerve hypertrophy could not predict the results of electrophysiological and histological examinations. PMID:2749098

  12. Temperature dependence of gating current in myelinated nerve fibers

    Microsoft Academic Search

    Peter Jonas

    1989-01-01

    Summary Asymmetrical displacement currents and Na currents of single myelinated nerve fibers ofXenopus laevis were studied in the temperature range from 5 to 24°C. The time constant of the on-response atE=4 mV,ton, was strongly temperature dependent, whereas the amount of displaced charge atE=39 mV, Qon, was only slightly temperature dependent. The mean Q10 forton-1 was 2.54, the mean Q10 for

  13. Ultrasonography of peripheral nerves.

    PubMed

    Martinoli, C; Bianchi, S; Derchi, L E

    2000-06-01

    With recent improvements in ultrasound (US) imaging equipment and refinements in scanning technique, an increasing number of peripheral nerves and related pathologic conditions can be identified. US imaging can support clinical and electrophysiologic testing for detection of nerve abnormalities caused by trauma, tumors, and a variety of nonneoplastic conditions, including entrapment neuropathies. This article addresses the normal US appearance of peripheral nerves and discusses the potential role of US nerve imaging in specific clinical settings. A series of US images of diverse pathologic processes involving peripheral nerves is presented. PMID:10994689

  14. Optic Nerve Elongation

    PubMed Central

    Alvi, Aijaz; Janecka, Ivo P.; Kapadia, Silloo; Johnson, Bruce L.; McVay, William

    1996-01-01

    The length of the optic nerves is a reflection of normal postnatal cranio-orbital development. Unilateral elongation of an optic nerve has been observed in two patients with orbital and skull base neoplasms. In the first case as compared to the patient's opposite, normal optic nerve, an elongated length of the involved optic nerve of 45 mm was present. The involved optic nerve in the second patient was 10 mm longer than the normal opposite optic nerve. The visual and extraocular function was preserved in the second patient. The first patient had only light perception in the affected eye. In this paper, the embryology, anatomy, and physiology of the optic nerve and its mechanisms of stretch and repair are discussed. ImagesFigure 1Figure 2Figure 3Figure 4Figure 5Figure 6Figure 7Figure 8Figure 9Figure 10Figure 11Figure 13 PMID:17170975

  15. An unusual complication of ulnar nerve entrapment in a pediatric olecranon fracture: a case report.

    PubMed

    Ertem, Kadir

    2009-05-01

    The rates of rare complications of acute or late ulnar nerve entrapment after supracondylar fractures, medial condyl fractures, elbow dislocations, forearm fractures, Galeazzi fracture dislocations, and epiphyseal separation of the distal ulna were reported earlier in the literature. Here, we report a late ulnar nerve entrapment after displaced olecranon fracture in a 10-year-old boy. PMID:19369899

  16. Internal Displacement Monitoring Centre

    NSDL National Science Digital Library

    The Internal Displacement Monitoring Centre (IDMC) was established twelve years ago in the hope that they would "raise awareness of the plight of internally displaced people (IDP), point to gaps in national and international responses and promote solutions reflecting international standards and best practices." The Centre also keeps a database of 50 countries in which people have been displaced within their own country due to conflicts or human rights violations. To get a sense of where displaced persons are and how many countries have IDPs, visitors can click on the small world map on the far right hand side of the homepage. Scrolling over the map will reveal the number of displaced people by continent. Visitors interested in learning about an individual country can click on the continent, then click on one of the countries for an "Internal Displacement Profile", "Country Statistics", and an "Overview". The Resources tab, at the top of any page, includes "IDMC Publications", "Picture Galleries" of internally displaced people in India, Cyprus, and the West Bank, to name a few, and "IDP Maps" which has dozens of maps of from 2001 to 2009.

  17. Kinematics Problem: Displacement

    NSDL National Science Digital Library

    Wolfgang Christian

    A bowling ball is lifted from rest onto a shelf by an external agent (position is in meters and time is in seconds). Rank the paths by the displacement of the bowling ball during the animations (greatest first).

  18. Inversion of displacement operators

    Microsoft Academic Search

    V. Y. Pan; X. Wang

    2002-01-01

    Abstract. We recall briefly the displacement rankapproach to the computations,with struc- tured matrices, which we trace backto the seminal paper by Kailath, Kung, and Morf [ J. Math. Anal. Appl., 68 (1979), pp. 395–407]. The concluding stage of the computations is the recovery of the output from its compressed,representation via the associated displacement operator L. The recovery amounts to the

  19. Advantages of Digital Subtraction Angiography During Nerve Block

    PubMed Central

    Park, Sun kyung; Choi, Yun Suk

    2014-01-01

    Introduction: Most pain physicians know that fluoroscopy might improve the safety, accuracy, and efficacy of nerve block; however, it is difficult to distinguish the previously administered contrast medium from the injecting contrast medium, and to identify accurate contrast medium diffusion flow in a case of existing radiodensities such as cement and screw. Digital subtraction angiography (DSA) can improve accuracy of nerve blocks. Case Presentation: We described our experiences with two successful transforaminal epidural injections and nerve block of two patients with 73 and 68 years of age who were diagnosed as failed back surgery syndrome. Conclusions: The advantages of DSA in fluoroscopy-guided transforaminal epidural block and nerve block are identification of the degree of appropriate contrast flow (epidural and nerve root sleeve) and the intravascular administration without overlapping radiodense structures.

  20. Peripheral nerve regeneration and neurotrophic factors

    PubMed Central

    TERENGHI, GIORGIO

    1999-01-01

    The role of neurotrophic factors in the maintenance and survival of peripheral neuronal cells has been the subject of numerous studies. Administration of exogenous neurotrophic factors after nerve injury has been shown to mimic the effect of target organ-derived trophic factors on neuronal cells. After axotomy and during peripheral nerve regeneration, the neurotrophins NGF, NT-3 and BDNF show a well defined and selective beneficial effect on the survival and phenotypic expression of primary sensory neurons in dorsal root ganglia and of motoneurons in spinal cord. Other neurotrophic factors such as CNTF, GDNF and LIF also exert a variety of actions on neuronal cells, which appear to overlap and complement those of the neurotrophins. In addition, there is an indirect contribution of GGF to nerve regeneration. GGF is produced by neurons and stimulates proliferation of Schwann cells, underlining the close interaction between neuronal and glial cells during peripheral nerve regeneration. Different possibilities have been investigated for the delivery of growth factors to the injured neurons, in search of a suitable system for clinical applications. The studies reviewed in this article show the therapeutic potential of neurotrophic factors for the treatment of peripheral nerve injury and for neuropathies. PMID:10227662

  1. The Furcal Nerve Revisited

    PubMed Central

    Dabke, Harshad V.

    2014-01-01

    Atypical sciatica and discrepancy between clinical presentation and imaging findings is a dilemma for treating surgeon in management of lumbar disc herniation. It also constitutes ground for failed back surgery and potential litigations thereof. Furcal nerve (Furcal = forked) is an independent nerve with its own ventral and dorsal branches (rootlets) and forms a link nerve that connects lumbar and sacral plexus. Its fibers branch out to be part of femoral and obturator nerves in-addition to the lumbosacral trunk. It is most commonly found at L4 level and is the most common cause of atypical presentation of radiculopathy/sciatica. Very little is published about the furcal nerve and many are unaware of its existence. This article summarizes all the existing evidence about furcal nerve in English literature in an attempt to create awareness and offer insight about this unique entity to fellow colleagues/professionals involved in spine care. PMID:25317309

  2. The furcal nerve revisited.

    PubMed

    Harshavardhana, Nanjundappa S; Dabke, Harshad V

    2014-08-01

    Atypical sciatica and discrepancy between clinical presentation and imaging findings is a dilemma for treating surgeon in management of lumbar disc herniation. It also constitutes ground for failed back surgery and potential litigations thereof. Furcal nerve (Furcal = forked) is an independent nerve with its own ventral and dorsal branches (rootlets) and forms a link nerve that connects lumbar and sacral plexus. Its fibers branch out to be part of femoral and obturator nerves in-addition to the lumbosacral trunk. It is most commonly found at L4 level and is the most common cause of atypical presentation of radiculopathy/sciatica. Very little is published about the furcal nerve and many are unaware of its existence. This article summarizes all the existing evidence about furcal nerve in English literature in an attempt to create awareness and offer insight about this unique entity to fellow colleagues/professionals involved in spine care. PMID:25317309

  3. Overview of the Cranial Nerves

    MedlinePLUS

    ... nerves—the cranial nerves—lead directly from the brain to various parts of the head, neck, and trunk. Some of the cranial nerves are ... cranial nerves emerge from the underside of the brain, pass through ... to parts of the head, neck, and trunk. The nerves are named and numbered, ...

  4. Nerve and Blood Vessels

    Microsoft Academic Search

    Maura Valle; Maria Pia Zamorani

    From the histologic point of view, nerves are round or flattened cords, with a complex internal structure made of myelinated\\u000a and unmyelinated nerve fibers, containing axons and Schwann cells grouped in fascicles (Fig. 4.1a) (Erickson 1997). Along the course of the nerve, fibers can traverse from one fascicle to another and fascicles can split and merge. Based\\u000a on the fascicular

  5. ROOT WEEVILS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Numerous species of root weevil, Otiorhynchus spp. (Coleoptera: Curculionidae), infest hop. The black vine weevil, O. sulcatus (F.), is the dominant species infesting hop followed by the strawberry root weevil, O. ovatus (L.), rough strawberry root weevil, O. rugosostriatus Goeze, and O. meridional...

  6. Root Hairs

    PubMed Central

    Grierson, Claire; Nielsen, Erik; Ketelaarc, Tijs; Schiefelbein, John

    2014-01-01

    Roots hairs are cylindrical extensions of root epidermal cells that are important for acquisition of nutrients, microbe interactions, and plant anchorage. The molecular mechanisms involved in the specification, differentiation, and physiology of root hairs in Arabidopsis are reviewed here. Root hair specification in Arabidopsis is determined by position-dependent signaling and molecular feedback loops causing differential accumulation of a WD-bHLH-Myb transcriptional complex. The initiation of root hairs is dependent on the RHD6 bHLH gene family and auxin to define the site of outgrowth. Root hair elongation relies on polarized cell expansion at the growing tip, which involves multiple integrated processes including cell secretion, endomembrane trafficking, cytoskeletal organization, and cell wall modifications. The study of root hair biology in Arabidopsis has provided a model cell type for insights into many aspects of plant development and cell biology. PMID:24982600

  7. Optical displacement sensor

    DOEpatents

    Carr, Dustin W. (Albuquerque, NM)

    2008-04-08

    An optical displacement sensor is disclosed which uses a vertical-cavity surface-emitting laser (VCSEL) coupled to an optical cavity formed by a moveable membrane and an output mirror of the VCSEL. This arrangement renders the lasing characteristics of the VCSEL sensitive to any movement of the membrane produced by sound, vibrations, pressure changes, acceleration, etc. Some embodiments of the optical displacement sensor can further include a light-reflective diffractive lens located on the membrane or adjacent to the VCSEL to control the amount of lasing light coupled back into the VCSEL. A photodetector detects a portion of the lasing light from the VCSEL to provide an electrical output signal for the optical displacement sensor which varies with the movement of the membrane.

  8. Water displacement mercury pump

    DOEpatents

    Nielsen, M.G.

    1984-04-20

    A water displacement mercury pump has a fluid inlet conduit and diffuser, a valve, a pressure cannister, and a fluid outlet conduit. The valve has a valve head which seats in an opening in the cannister. The entire assembly is readily insertable into a process vessel which produces mercury as a product. As the mercury settles, it flows into the opening in the cannister displacing lighter material. When the valve is in a closed position, the pressure cannister is sealed except for the fluid inlet conduit and the fluid outlet conduit. Introduction of a lighter fluid into the cannister will act to displace a heavier fluid from the cannister via the fluid outlet conduit. The entire pump assembly penetrates only a top wall of the process vessel, and not the sides or the bottom wall of the process vessel. This insures a leak-proof environment and is especially suitable for processing of hazardous materials.

  9. Water displacement mercury pump

    DOEpatents

    Nielsen, Marshall G. (Woodside, CA)

    1985-01-01

    A water displacement mercury pump has a fluid inlet conduit and diffuser, a valve, a pressure cannister, and a fluid outlet conduit. The valve has a valve head which seats in an opening in the cannister. The entire assembly is readily insertable into a process vessel which produces mercury as a product. As the mercury settles, it flows into the opening in the cannister displacing lighter material. When the valve is in a closed position, the pressure cannister is sealed except for the fluid inlet conduit and the fluid outlet conduit. Introduction of a lighter fluid into the cannister will act to displace a heavier fluid from the cannister via the fluid outlet conduit. The entire pump assembly penetrates only a top wall of the process vessel, and not the sides or the bottom wall of the process vessel. This insures a leak-proof environment and is especially suitable for processing of hazardous materials.

  10. Propagation Speed in Myelinated Nerve

    PubMed Central

    Hardy, W. L.

    1973-01-01

    The Hodgkin-Huxley (H.H.) equations modified by Dodge for Rana pipiens myelinated nerve have been solved to determine how well the theory predicts the effects of changes of temperature and [Na+]0 on propagation. Conduction speed ? was found to have an approximately exponential dependence on temperature as was found experimentally, but the theoretical temperature coefficient (Q10) was low; 1.5 compared with the experimental finding of 2.95. ? was found to be a linear function of log ([Na+]0) in contrast to the experimental finding of a square root dependence on [Na+]0. ? is 50% greater at one-fourth normal [Na+]0 than the theory predicts. The difference between the theoretical ?([Na+]0) and the experimental ?([Na+]0) is probably due to an imprecisely known variation of parameters and not to a fundamental inadequacy of the theory. PMID:4542941

  11. Selective Reactions of Cutaneous and Muscle Afferent Neurons to Peripheral Nerve Transection in Rats

    Microsoft Academic Search

    Ping Hu; Elspeth M. McLachlan

    2003-01-01

    To determine whether peripheral nerve injury has similar effects on all functional types of afferent neuron, we retrogradely labeled populations of neurons projecting to skin and to muscle with FluoroGold and lesioned various peripheral nerves in the rat. Labeled neurons were counted after different periods and related to immunohistochemically identified ectopic terminals and satellite cells in lumbar dorsal root ganglia.

  12. Patient-specific factors in the proximity of the inferior alveolar nerve to the tooth apex

    PubMed Central

    Adigüzel, Özkan; Kaya, Sadullah; Akku?, Zeki

    2012-01-01

    Objectives: To evaluate whether age and gender differences are predictive factors for inferior alveolar nerve position with respect to mandibular first molar roots. Study Design: Cone-beam computed tomography scans [0.2-mm3 voxel size; n = 200 (100 males, 100 females)] of patients aged 15–65 years showing mandibular first and second molars were included in this study. Patients with pathoses that might affect inferior alveolar nerve position, including second molar and/or first premolar extraction, were excluded. Fourteen measurements (mm) were taken from the inferior alveolar nerve to the mesial and distal root apices. Subjects were grouped by age and gender. Data were analysed using two-way analyses of variance with post hoc Bonferroni corrections. Results: The distance from the inferior alveolar nerve to the root apices was smaller in females than males, regardless of age (p < 0.01). Distal roots were closer to the nerve than mesial roots in both genders (p < 0.05). Total buccolingual mandibular length (at 3-mm apical level) was shorter in females than males (p < 0.01) but mean buccolingual mandibular width at the level of the inferior alveolar canal did not differ. Nerve–root apex distances were significantly shorter in males and females aged 16–25 and 56–65 years than in other age groups (p < 0.01). Conclusions: The distance between inferior alveolar nerve and mandibular first molar roots depends upon the age and gender: it is shorter in females than in males and in subjects aged 16–25 years and >55 years than in other age groups. Key words:Age, cone-beam computed tomography, inferior alveolar nerve, root apex, gender. PMID:22926478

  13. In Vivo Contrast-Enhanced MR Imaging of Direct Infusion into Rat Peripheral Nerves

    PubMed Central

    Chen, Xiaoming; Astary, Garrett W.; Mareci, Thomas H.; Sarntinoranont, Malisa

    2011-01-01

    Direct infusion, or convection-enhanced delivery (CED), into peripheral nerves may provide a method for delivering substances to the intrathecal space or specific fiber bundles entering the spinal cord. To better understand this potential delivery technique, we have characterized the extracellular transport of macromolecular agents from peripheral nerves to the spinal cord in magnetic resonance (MR) imaging studies. High-resolution dynamic contrast-enhanced MR imaging at 11.1 T was used to monitor and characterize in vivo the extracellular transport dynamics of Gd-DTPA-albumin tracer during CED into rat sciatic nerves. Extracellular tracers followed peripheral nerves towards the spinal cord and at vertebral levels L4 and L5 appeared to enter the cerebrospinal fluid and nerve roots. Uptake directly into spinal cord tissues (white and gray matter) appeared to be limited. Spatial distribution patterns within spinal cord regions depended on CED factors, including cannula placement, and underlying tissue structures including peripheral nerve branching and membrane structures at nerve root entry. The applied MR techniques allowed for visualization and quantification of tracer spread and distribution within the rat spinal cord region. The results show that CED into peripheral nerves provides an alternative route for delivering therapeutics to nerve roots and the intrathecal space surrounding the spinal cord. PMID:21809145

  14. High-resolution ultrasonography for the diagnosis of brachial plexus root lesions.

    PubMed

    Zhu, Yong-Sheng; Mu, Nan-Nan; Zheng, Min-Juan; Zhang, Yun-Chu; Feng, Hua; Cong, Rui; Zhou, Xiao-Dong; Chen, Ding-Zhang

    2014-07-01

    The aim of this study was to investigate the feasibility of using high-resolution ultrasonography in the diagnosis of brachial plexus (BP) root lesions. A prospective study of ultrasonographic evaluation of BP nerve roots was performed in 37 patients with BP root lesions (29 with root injuries, 8 with tumors). The pre-operative ultrasonographic findings were compared with the surgical and pathohistological findings. All C5-7 roots were detected by ultrasonography in all patients, whereas 92% (68/74) of C8 and 51% (38/74) of T1 nerve roots were visualized. Among 29 patients with BP root avulsion, partial injuries or totally interrupted BP roots were detected in all patients. Cystic masses and neuromas were detected in 16 and 23 patients, respectively. In 8 patients with BP root tumors, 8 hypo-echoic masses were detected inside or partly outside of intervertebral foramina connecting to nerve roots. Surgical exploration revealed that there were 57 BP root avulsions in 29 patients. However, 2 T1 nerve root avulsions had been missed by pre-operative ultrasonography. Pathohistology revealed that all 8 BP root tumors pre-operatively diagnosed by ultrasonography were schwannomas. High-resolution ultrasonography can provide a convenient and accurate imaging modality for quick diagnosis and location of BP root lesions. PMID:24768481

  15. Chemotropism in nerve regeneration studied in tissue culture.

    PubMed Central

    Gu, X; Thomas, P K; King, R H

    1995-01-01

    The neurotropic effect of the distal stump of transected sciatic nerve on regenerating axons emerging from the proximal stump was investigated in rats by the coculture of excised neonatal dorsal root ganglia and segments of degenerated and nondegenerated sciatic nerves. In all cultures, neurites from the ganglion extended directly towards the degenerated distal stump and not towards the undegenerated nerve segment. Analysis of the supernatants of nerve homogenates by native polyacrylamide gel electrophoresis demonstrated that 250 and 18 kDa proteins were upregulated in the degenerated distal stumps and that 89, 67 and 65 kDa proteins were expressed by these stumps but not by normal nerve. Placement of the individual protein strips, cut from the gels, in dissociated cultures of dorsal root ganglion cells showed that the 89 and 18 kDa strips possessed strong neurotropic activity. Neurons survived selectively on these strips and outgrowing neurites elongated on the strips, parallel to the direction of the band. When explanted dorsal root ganglia were cultured along with the strips, outgrowing neurites extended selectively towards those containing the 89 and 18 kDa bands. It is concluded that these bands contain chemotropic substances, the nature of which requires further investigation. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 10 Fig. 11 Fig. 12 PMID:7649810

  16. [The comparative characteristics of the age-related changes in the rate of fast axonal transport in the vagus and hypoglossal nerves and in the ventral spinal cord roots of rats].

    PubMed

    Tanin, S A; Martsinko, V I

    1990-01-01

    The study was undertaken on the fast axonal transport (FAT) of 3H- or 14C-leucine labelled substances along the n. vagus, n. hypoglossus and ventral roots of the spinal cord in adult (8-10 months) and old (26-28 months) male rats after the label administration into nucleus ambiguus, nucleus hypoglossus, and the area of the ventral horn of the spinal cord, respectively. It has been found that in old rats compared to adult animals the rate of FAT along the n. vagus decreased from 552 +/- 12.7 mm to 252 +/- 13 mm per 24 hours; along the n. hypoglossus--from 492 +/- 38 mm to 216 mm per 24 hours; and along the ventral L5 and L6 roots--from 408 +/- 10.9 mm to 217 +/- 11.3 mm per 24 hours. It is suggested that age-related functional shifts in n. vagus influencing the heart are, to some degree, determined by the most significant disturbances of FAT substances in it. PMID:1702188

  17. The nerve injury and the dying neurons: diagnosis and prevention.

    PubMed

    Terenghi, Giorgio; Hart, Andrew; Wiberg, Mikael

    2011-11-01

    Following distal nerve injury significant sensory neuronal cell death occurs in the dorsal root ganglia, while after a more proximal injury, such as brachial plexus injury, a sizeable proportion of spinal motoneurons also undergo cell death. This phenomenon has been undervalued for a long time, but it has a significant role in the lack of functional recuperation, as neuronal cells cannot divide and be replaced, hence the resulting nerve regeneration is usually suboptimal. It is now accepted that this cell death is due to apoptosis, as indicated by analysis of specific genes involved in the apoptotic signalling cascade. Immediate nerve repair, either by direct suturing or nerve grafting, gives a degree of neuroprotection, but this approach does not fully prevent neuronal cell death and importantly it is not always possible. Our work has shown that pharmacological intervention using either acetyl-L-carnitine (ALCAR) or N-acetyl-cysteine (NAC) give complete neuroprotection in different types of peripheral nerve injury. Both compounds are clinically safe and experimental work has defined the best dose, timing after injury and duration of administration. The efficacy of neuroprotection of ALCAR and NAC can be monitored non-invasively using MRI, as demonstrated experimentally and more recently by clinical studies of the volume of dorsal root ganglia. Translation to patients of this pharmacological intervention requires further work, but the available results indicate that this approach will help to secure a better functional outcome following peripheral nerve injury and repair. PMID:22058229

  18. Selective vulnerability of peripheral nerves in avian riboflavin deficiency demyelinating polyneuropathy.

    PubMed

    Cai, Z; Blumbergs, P C; Finnie, J W; Manavis, J; Thompson, P D

    2009-01-01

    Riboflavin (vitamin B2) deficiency in young chickens produces a demyelinating peripheral neuropathy. In this study, day-old broiler meat chickens were fed a riboflavin-deficient diet (1.8 mg/kg) and killed on posthatch days 6, 11, 16, 21, and 31, while control chickens were given a conventional diet containing 5.0 mg/kg riboflavin. Pathologic changes were found in sciatic, cervical, and lumbar spinal nerves of riboflavin-deficient chickens from day 11 onwards, characterized by endoneurial oedema, hypertrophic Schwann cells, tomacula (redundant myelin swellings), demyelination/remyelination, lipid deposition, and fibroblastic onion bulb formation. Similar changes were also found in large and medium intramuscular nerves, although they were less severe in the latter. However, by contrast, ventral and dorsal spinal nerve roots, distal intramuscular nerves, and subcutaneous nerves were normal at all time points examined. These findings demonstrate, for the first time, that riboflavin deficiency in young, rapidly growing chickens produces selective injury to peripheral nerve trunks, with relative sparing of spinal nerve roots and distal nerve branches to muscle and skin. These novel findings suggest that the response of Schwann cells in peripheral nerves with riboflavin deficiency differs because either there are subsets of these cells in, or there is variability in access of nutrients to, different sites within the nerves. PMID:19112122

  19. Advances in nerve repair.

    PubMed

    Khuong, Helene T; Midha, Rajiv

    2013-01-01

    Patients with peripheral nerve injuries face unpredictable and often suboptimal functional outcome, even following standard microsurgical nerve repair. The challenge of improving such outcomes following nerve surgical procedures has interested many research teams, in both clinical and fundamental fields. Some innovative treatments are presently being applied to a widening range of patients, whereas others will require further development before translation to human subjects. This article presents several recent advances in emerging therapies at various stages of clinical application. Nerve transfers have been successfully used in clinical settings, but new indications are being described, enlarging the range of patients who might benefit from them. Brief direct nerve electrical stimulation has been shown to improve nerve regeneration and outcome in animal models and in a small cohort of patients. Further clinical trials are warranted to prove the efficacy of this exciting and easily applicable approach. Animal studies also suggest a tremendous potential for stem and precursor cell therapy. Further studies will lead to a better understanding of their mechanisms of action in nerve repair and potential applications for human patients. PMID:23250767

  20. Changes in nerve microcirculation following peripheral nerve compression?

    PubMed Central

    Gao, Yueming; Weng, Changshui; Wang, Xinglin

    2013-01-01

    Following peripheral nerve compression, peripheral nerve microcirculation plays important roles in regulating the nerve microenvironment and neurotrophic substances, supplying blood and oxygen and maintaining neural conduction and axonal transport. This paper has retrospectively analyzed the articles published in the past 10 years that addressed the relationship between peripheral nerve compression and changes in intraneural microcirculation. In addition, we describe changes in different peripheral nerves, with the aim of providing help for further studies in peripheral nerve microcirculation and understanding its protective mechanism, and exploring new clinical methods for treating peripheral nerve compression from the perspective of neural microcirculation. PMID:25206398

  1. Heavy metal displacement in chelate-irrigated soil during phytoremediation

    Microsoft Academic Search

    M. S Liphadzi; M. B Kirkham

    2003-01-01

    Heavy metals in wastewater sewage sludge (biosolids), applied to land, contaminate soils. Phytoremediation, the use of plants to clean up toxic heavy metals, might remove them. Chelating agents are added to soil to solubilize the metals for enhanced phytoextraction. Yet no studies follow the displacement and leaching of heavy metals in soil with and without roots following solubilization with chelates.

  2. Anterior interosseous nerve syndrome

    PubMed Central

    Bäumer, Philipp; Meinck, Hans-Michael; Schiefer, Johannes; Weiler, Markus; Bendszus, Martin; Kele, Henrich

    2014-01-01

    Objective: We sought to determine lesion sites and spatial lesion patterns in spontaneous anterior interosseous nerve syndrome (AINS) with high-resolution magnetic resonance neurography (MRN). Methods: In 20 patients with AINS and 20 age- and sex-matched controls, MRN of median nerve fascicles was performed at 3T with large longitudinal anatomical coverage (upper arm/elbow/forearm): 135 contiguous axial slices (T2-weighted: echo time/repetition time 52/7,020 ms, time of acquisition: 15 minutes 48 seconds, in-plane resolution: 0.25 × 0.25 mm). Lesion classification was performed by visual inspection and by quantitative analysis of normalized T2 signal after segmentation of median nerve voxels. Results: In all patients and no controls, T2 lesions of individual fascicles were observed within upper arm median nerve trunk and strictly followed a somatotopic/internal topography: affected were those motor fascicles that will form the anterior interosseous nerve further distally while other fascicles were spared. Predominant lesion focus was at a mean distance of 14.6 ± 5.4 cm proximal to the humeroradial joint. Discriminative power of quantitative T2 signal analysis and of qualitative lesion rating was high, with 100% sensitivity and 100% specificity (p < 0.0001). Fascicular T2 lesion patterns were rated as multifocal (n = 17), monofocal (n = 2), or indeterminate (n = 1) by 2 independent observers with strong agreement (kappa = 0.83). Conclusion: It has been difficult to prove the existence of fascicular/partial nerve lesions in spontaneous neuropathies using clinical and electrophysiologic findings. With MRN, fascicular lesions with strict somatotopic organization were observed in upper arm median nerve trunks of patients with AINS. Our data strongly support that AINS in the majority of cases is not a surgically treatable entrapment neuropathy but a multifocal mononeuropathy selectively involving, within the main trunk of the median nerve, the motor fascicles that continue distally to form the anterior interosseous nerve. PMID:24415574

  3. Modeling root reinforcement using a root-failure Weibull survival function

    NASA Astrophysics Data System (ADS)

    Schwarz, M.; Giadrossich, F.; Cohen, D.

    2013-11-01

    Root networks contribute to slope stability through complex interactions with soil that include mechanical compression and tension. Due to the spatial heterogeneity of root distribution and the dynamics of root turnover, the quantification of root reinforcement on steep slopes is challenging and consequently the calculation of slope stability also. Although considerable progress has been made, some important aspects of root mechanics remain neglected. In this study we address specifically the role of root-strength variability on the mechanical behavior of a root bundle. Many factors contribute to the variability of root mechanical properties even within a single class of diameter. This work presents a new approach for quantifying root reinforcement that considers the variability of mechanical properties of each root diameter class. Using the data of laboratory tensile tests and field pullout tests, we calibrate the parameters of the Weibull survival function to implement the variability of root strength in a numerical model for the calculation of root reinforcement (RBMw). The results show that, for both laboratory and field data sets, the parameters of the Weibull distribution may be considered constant with the exponent equal to 2 and the normalized failure displacement equal to 1. Moreover, the results show that the variability of root strength in each root diameter class has a major influence on the behavior of a root bundle with important implications when considering different approaches in slope stability calculation. Sensitivity analysis shows that the calibration of the equations of the tensile force, the elasticity of the roots, and the root distribution are the most important steps. The new model allows the characterization of root reinforcement in terms of maximum pullout force, stiffness, and energy. Moreover, it simplifies the implementation of root reinforcement in slope stability models. The realistic quantification of root reinforcement for tensile, shear and compression behavior allows for the consideration of the stabilization effects of root networks on steep slopes and the influence that this has on the triggering of shallow landslides.

  4. [Nerve injuries in children].

    PubMed

    Legré, R; Iniesta, A; Toméi, F; Gay, A

    2013-09-01

    Management of peripheral nerve lesions in children does not differ fundamentally from that in adults. Nevertheless, difficulty to perform an extensive clinical examination can explain initial misdiagnosis and postoperative follow up can be tricky. The poor compliance of the children in the postoperative care makes a postoperative immobilization mandatory. If the peripheral nerve injuries involving children have a better prognosis reputation than in adults, fundamental studies results do not comfort this conventional wisdom, but rather claim for a better adaptability of the child to the relapses left by the peripheral nerves lesions. PMID:23751426

  5. A novel chondroitin sulfate hydrogel for nerve repair

    NASA Astrophysics Data System (ADS)

    Conovaloff, Aaron William

    Brachial plexus injuries affect numerous patients every year, with very debilitating results. The majority of these cases are very severe, and involve damage to the nerve roots. To date, repair strategies for these injuries address only gross tissue damage, but do not supply cells with adequate regeneration signals. As a result, functional recovery is often severely lacking. Therefore, a chondroitin sulfate hydrogel that delivers neurotrophic signals to damaged neurons is proposed as a scaffold to support nerve root regeneration. Capillary electrophoresis studies revealed that chondroitin sulfate can physically bind with a variety of neurotrophic factors, and cultures of chick dorsal root ganglia demonstrated robust neurite outgrowth in chondroitin sulfate hydrogels. Outgrowth in chondroitin sulfate gels was greater than that observed in control gels of hyaluronic acid. Furthermore, the chondroitin sulfate hydrogel's binding activity with nerve growth factor could be enhanced by incorporation of a synthetic bioactive peptide, as revealed by fluorescence recovery after photobleaching. This enhanced binding was observed only in chondroitin sulfate gels, and not in hyaluronic acid control gels. This enhanced binding activity resulted in enhanced dorsal root ganglion neurite outgrowth in chondroitin sulfate gels. Finally, the growth of regenerating dorsal root ganglia in these gels was imaged using label-free coherent anti-Stokes scattering microscopy. This technique generated detailed, high-quality images of live dorsal root ganglion neurites, which were comparable to fixed, F-actin-stained samples. Taken together, these results demonstrate the viability of this chondroitin sulfate hydrogel to serve as an effective implantable scaffold to aid in nerve root regeneration.

  6. Displacement and Velocity Ratios

    NSDL National Science Digital Library

    Bourassa, James

    This interactive presentation, created by James Bourassa and John Rosz for the Electromechanical Digital Library, discusses displacement and velocity ratios. Bourassa and Rosz begin by providing detailed definitions of both topics and then provide mathematical examples of each. Once this basic explanation is complete, the authors allow students to practice these theories in a set of self-correcting quiz questions. Bourassa and Rosz explain each using helpful interactive flash animations. These are not only useful in explanation, but they allow the student to more fully engage with the topic. Overall, this is a nice introduction to the physical and mathematical concepts of displacement and velocity ratios. This could be a valuable learning resource in everything from a physics to a technical education classroom.

  7. Electrophysiological properties were monitored in detail in chronically con-stricted peripheral nerves by implanted, multicontact nerve cuff electrodes

    E-print Network

    Loeb, Gerald E.

    similar but less pronounced changes than larger diameter fibers. Recordings from ventral and dorsal roots * "dying-back" degeneration * secondary demyelination MUSCLE & NERVE 12:915-928 1989 CONDUCTION STUDIES of traumatic lesions. Retrograde rofilament transport from the cell-body in re- atrophy of mature peripheral

  8. Above Water: Buoyancy & Displacement

    NSDL National Science Digital Library

    2013-12-18

    In an investigation called "Shape It!" learners craft tiny boats out of clay, set them afloat on water and then add weight loads to them, in order to explore: how objects stay afloat in water; what the relationship is among surface tension, buoyancy, density and displacement; and how shape, size, and type of material affect an object's ability to remain buoyant. The introductory text discusses how heavy steel ships can float on bodies of water like rivers, bays and oceans.

  9. RTV 21 Displacements

    SciTech Connect

    Kurita, C.H.; /Fermilab

    1987-02-04

    A seal is needed for the cover of the Nitrogen Test Vessel in order to prevent leakage of the N{sub 2} gas. This seal is to be molded out of RTV 21. In this experiment, the Modulus of Elasticity of the RTV was sought after, and the displacements of the RTV due to various stresses were measured to see if they were large enough to provide a tight seal between the vessel and its cover.

  10. Metastatic renal cell carcinoma mimicking a schwannoma in a dorsal root ganglion: case report.

    PubMed

    Wasserman, Jason K; Tsai, Eve C; Glikstein, Rafael; Mai, Kien T; Jansen, Gerard H

    2015-03-01

    Peripheral nerve tumors are soft-tissue tumors that can occur in any nerve throughout the body. The majority of peripheral nerve tumors arise from elements of the nerve sheath with the two most common being neurofibromas and schwannomas. More than 90% of all peripheral nerve tumors are benign. When there is peripheral nerve involvement in metastatic carcinoma, it is often via contiguous spread from the primary mass; hematogenous seeding to a peripheral nerve is seldom seen. In this report the authors describe the even rarer case of metastatic renal cell carcinoma mimicking a schwannoma in a dorsal root ganglion. Cases from the literature show the rarity of this finding and its late clinical appearance. Given that survival in patients with metastatic carcinoma continues to increase, dorsal root ganglion metastasis may become more common over time. PMID:25555049

  11. A review of the thoracic splanchnic nerves and celiac ganglia.

    PubMed

    Loukas, Marios; Klaassen, Zachary; Merbs, William; Tubbs, R Shane; Gielecki, Jerzy; Zurada, Anna

    2010-07-01

    Anatomical variation of the thoracic splanchnic nerves is as diverse as any structure in the body. Thoracic splanchnic nerves are derived from medial branches of the lower seven thoracic sympathetic ganglia, with the greater splanchnic nerve comprising the more cranial contributions, the lesser the middle branches, and the least splanchnic nerve usually T11 and/or T12. Much of the early anatomical research of the thoracic splanchnic nerves revolved around elucidating the nerve root level contributing to each of these nerves. The celiac plexus is a major interchange for autonomic fibers, receiving many of the thoracic splanchnic nerve fibers as they course toward the organs of the abdomen. The location of the celiac ganglia are usually described in relation to surrounding structures, and also show variation in size and general morphology. Clinically, the thoracic splanchnic nerves and celiac ganglia play a major role in pain management for upper abdominal disorders, particularly chronic pancreatitis and pancreatic cancer. Splanchnicectomy has been a treatment option since Mallet-Guy became a major proponent of the procedure in the 1940s. Splanchnic nerve dissection and thermocoagulation are two common derivatives of splanchnicectomy that are commonly used today. Celiac plexus block is also a treatment option to compliment splanchnicectomy in pain management. Endoscopic ultrasonography (EUS)-guided celiac injection and percutaneous methods of celiac plexus block have been heavily studied and are two important methods used today. For both splanchnicectomies and celiac plexus block, the innovation of ultrasonographic imaging technology has improved efficacy and accuracy of these procedures and continues to make pain management for these diseases more successful. PMID:20235178

  12. Degenerative Nerve Diseases

    MedlinePLUS

    Degenerative nerve diseases affect many of your body's activities, such as balance, movement, talking, breathing, and heart function. Many of these diseases are genetic. Sometimes the cause is a medical ...

  13. Diabetic Nerve Problems

    MedlinePLUS

    ... the wrong times. This damage is called diabetic neuropathy. Over half of people with diabetes get it. ... change positions quickly Your doctor will diagnose diabetic neuropathy with a physical exam and nerve tests. Controlling ...

  14. Common peroneal nerve dysfunction

    MedlinePLUS

    ... people: Who are very thin (for example, from anorexia nervosa ) Who have conditions such as diabetic neuropathy or ... other tests are done depend on the suspected cause of nerve dysfunction, and the person's symptoms and ...

  15. Vagus Nerve Stimulation.

    PubMed

    Howland, Robert H

    2014-06-01

    The vagus nerve is a major component of the autonomic nervous system, has an important role in the regulation of metabolic homeostasis, and plays a key role in the neuroendocrine-immune axis to maintain homeostasis through its afferent and efferent pathways. Vagus nerve stimulation (VNS) refers to any technique that stimulates the vagus nerve, including manual or electrical stimulation. Left cervical VNS is an approved therapy for refractory epilepsy and for treatment resistant depression. Right cervical VNS is effective for treating heart failure in preclinical studies and a phase II clinical trial. The effectiveness of various forms of non-invasive transcutaneous VNS for epilepsy, depression, primary headaches, and other conditions has not been investigated beyond small pilot studies. The relationship between depression, inflammation, metabolic syndrome, and heart disease might be mediated by the vagus nerve. VNS deserves further study for its potentially favorable effects on cardiovascular, cerebrovascular, metabolic, and other physiological biomarkers associated with depression morbidity and mortality. PMID:24834378

  16. Optic Nerve Decompression

    MedlinePLUS

    ... sinuses directly beside the eye. In particular, the ethmoid and sphenoid sinuses are directly adjacent to the ... double vision, inadequate decompression of the optic nerve, bleeding around the eye, carotid artery injury, leakage of ...

  17. Extratemporal facial nerve injury.

    PubMed

    Sternbach, G L; Rosen, P; Meislin, H W

    1976-04-01

    Isolated traumatic facial nerve injury, frequently seen in wartime combat, may also be encountered among civilians. The clinical picture occurring as a result of such injury may be confusing because partial, or incomplete, damage to the peripheral nerve may mimic impairment of the central facial motor mechanism. In treating the patient with facial injury, life-threatening aspects of the injury must be assessed and stabilized first. Then, attention may be focused on the injured facial nerve, for which prompt surgical repair is the treatment of choice. Prior to surgery, the assessment of taste and hearing, as well as mastoid and skull x-ray films and electrodiagnostic tests are helpful in localizing the facial nerve injury. PMID:933404

  18. Ulnar nerve dysfunction

    MedlinePLUS

    Katirji B, Koontz D. Disorders of peripheral nerves. In: Daroff RB, Fenichel GM, Jankovic J, Mazziotta JC, eds. Bradley’s Neurology in Clinical Practice . 6th ed. Philadelphia, Pa: Saunders Elsevier; 2012: ...

  19. Tibial nerve dysfunction

    MedlinePLUS

    Katitji B, Koontz D. Disorders of the peripheral nerves. In: Daroff RB, Fenichel GM, Jankovic J, Mazziotta JC. Bradley's Neurology in Clinical Practice. 6th ed. Philadelphia, PA: Elsevier Saunders; 2012:chap 76. ...

  20. Axillary nerve dysfunction

    MedlinePLUS

    ... Body-wide (systemic) disorders that cause nerve inflammation Deep infection Fracture of the upper arm bone (humerus) Pressure from casts or splints Improper use of crutches Shoulder dislocation In some cases, no cause can be found.

  1. Dentoalveolar nerve injury.

    PubMed

    Auyong, Thomas G; Le, Anh

    2011-08-01

    Nerve injury associated with dentoalveolar surgery is a complication contributing to the altered sensation of the lower lip, chin, buccal gingivae, and tongue. This surgery-related sensory defect is a morbid postoperative outcome. Several risk factors have been proposed. This article reviews the incidence of trigeminal nerve injury, presurgical risk assessment, classification, and surgical coronectomy versus conventional extraction as an approach to prevent neurosensory damage associated with dentoalveolar surgery. PMID:21798439

  2. Bladder emptying by intermittent electrical stimulation of the pudendal nerve

    NASA Astrophysics Data System (ADS)

    Boggs, Joseph W.; Wenzel, Brian J.; Gustafson, Kenneth J.; Grill, Warren M.

    2006-03-01

    Persons with a suprasacral spinal cord injury cannot empty their bladder voluntarily. Bladder emptying can be restored by intermittent electrical stimulation of the sacral nerve roots (SR) to cause bladder contraction. However, this therapy requires sensory nerve transection to prevent dyssynergic contraction of the external urethral sphincter (EUS). Stimulation of the compound pudendal nerve trunk (PN) activates spinal micturition circuitry, leading to a reflex bladder contraction without a reflex EUS contraction. The present study determined if PN stimulation could produce bladder emptying without nerve transection in cats anesthetized with ?-chloralose. With all nerves intact, intermittent PN stimulation emptied the bladder (64 ± 14% of initial volume, n = 37 across six cats) more effectively than either distention-evoked micturition (40 ± 19%, p < 0.001, n = 27 across six cats) or bilateral intermittent SR stimulation (25 ± 23%, p < 0.005, n = 4 across two cats). After bilateral transection of the nerves innervating the urethral sphincter, intermittent SR stimulation voided 79 ± 17% (n = 12 across three cats), comparable to clinical results obtained with SR stimulation. Voiding via intermittent PN stimulation did not increase after neurotomy (p > 0.10), indicating that PN stimulation was not limited by bladder-sphincter dyssynergia. Intermittent PN stimulation holds promise for restoring bladder emptying following spinal injury without requiring nerve transection.

  3. Histopathological effects of radiosurgery on a human trigeminal nerve

    PubMed Central

    Al-Otaibi, Faisal; Alhindi, Hindi; Alhebshi, Adnan; Albloushi, Monirah; Baeesa, Saleh; Hodaie, Mojgan

    2013-01-01

    Background: Radiosurgery is a well-established treatment modality for medically refractory trigeminal neuralgia. The exact mechanism of pain relief after radiosurgery is not clearly understood. Histopathology examination of the trigeminal nerve in humans after radiosurgery is rarely performed and has produced controversial results. Case Description: We report on a 45-year-old female who received radiosurgery treatment for trigeminal neuralgia by Cyberknife. A 6-mm portion of the cisternal segment of trigeminal nerve received a dose of 60 Gy. The clinical benefit started 10 days after therapy and continued for 8 months prior to a recurrence of her previous symptoms associated with mild background pain. She underwent microvascular decompression and partial sensory root sectioning. Atrophied trigeminal nerve rootlets were grossly noted intraoperatively under surgical microscope associated with changes in trigeminal nerve color to gray. A biopsy from the inferolateral surface of the nerve proximal to the midcisternal segment showed histological changes in the form of fibrosis and axonal degeneration. Conclusion: This case study supports the evidence of histological damage of the trigeminal nerve fibers after radiosurgery therapy. Whether or not the presence and degree of nerve damage correlate with the degree of clinical benefit and side effects are not revealed by this study and need to be explored in future studies. PMID:24605252

  4. Roots and Root Function: Introduction

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A number of current issues related to water management, ecohydrology, and climate change are giving impetus to new research aimed at understanding roots and their functioning. Current areas of research include: use of advanced imaging technologies such as Magnetic Resonance Imaging to observe roots...

  5. Nerve conduction study of the medial and lateral plantar nerves.

    PubMed

    Antunes, A C; Nobrega, J A; Manzano, G M

    2000-01-01

    The medial and lateral plantar nerves may be evaluated through the recordings of the compound sensory nerve action potentials (CSNAP), compound mixed nerve action potentials (CMNAP) and compound muscular action potentials (CMAP). As some of these potentials are not easily and always obtainable in normal individuals, our purpose was to verify the consistency of these potentials for the study of these nerves. Fifty-one normal adult volunteers were examined. The CSNAP, CMNAP and CMAP, related to the medial and lateral plantar nerves were evaluated bilaterally. CSNAP were not obtained in 7.8% and in 17.6% from the medial and lateral plantar nerves respectively. CMNAP from the lateral plantar nerve were not obtained in 15.6%. CMNAP from the medial plantar nerves and CMAPs from the abductor hallucis and abductor digiti quinti were obtained for all nerves tested. Our results, therefore, suggest that these last 3 parameters are the ones more reliable for clinical application. PMID:10812535

  6. Synthesis of finite displacements and displacements in continental margins

    NASA Technical Reports Server (NTRS)

    Speed, R. C.; Elison, M. W.; Heck, F. R.; Russo, R. M.

    1988-01-01

    The scope of the project is the analysis of displacement-rate fields in the transitional regions between cratonal and oceanic lithospheres over Phanerozoic time (last 700 ma). Associated goals are an improved understanding of range of widths of major displacement zones; the partition of displacement gradients and rotations with position and depth in such zones; the temporal characteristics of such zones-the steadiness, episodicity, and duration of uniform versus nonunifrom fields; and the mechanisms and controls of the establishment and kinematics of displacement zones. The objective is to provide a context of time-averaged kinematics of displacement zones. The initial phase is divided topically among the methodology of measurement and reduction of displacements in the lithosphere and the preliminary analysis from geologic and other data of actual displacement histories from the Cordillera, Appalachians, and southern North America.

  7. Acellular Nerve Allografts in Peripheral Nerve Regeneration: A Comparative Study

    PubMed Central

    Moore, Amy M.; MacEwan, Matthew; Santosa, Katherine B.; Chenard, Kristofer E.; Ray, Wilson Z.; Hunter, Daniel A.; Mackinnon, Susan E.; Johnson, Philip J.

    2011-01-01

    Background Processed nerve allografts offer a promising alternative to nerve autografts in the surgical management of peripheral nerve injuries where short deficits exist. Methods Three established models of acellular nerve allograft (cold-preserved, detergent-processed, and AxoGen® -processed nerve allografts) were compared to nerve isografts and silicone nerve guidance conduits in a 14 mm rat sciatic nerve defect. Results All acellular nerve grafts were superior to silicone nerve conduits in support of nerve regeneration. Detergent-processed allografts were similar to isografts at 6 weeks post-operatively, while AxoGen®-processed and cold-preserved allografts supported significantly fewer regenerating nerve fibers. Measurement of muscle force confirmed that detergent-processed allografts promoted isograft-equivalent levels of motor recovery 16 weeks post-operatively. All acellular allografts promoted greater amounts of motor recovery compared to silicone conduits. Conclusions These findings provide evidence that differential processing for removal of cellular constituents in preparing acellular nerve allografts affects recovery in vivo. PMID:21660979

  8. Repair of sciatic nerve defects using tissue engineered nerves.

    PubMed

    Zhang, Caishun; Lv, Gang

    2013-07-25

    In this study, we constructed tissue-engineered nerves with acellular nerve allografts in Sprague-Dawley rats, which were prepared using chemical detergents-enzymatic digestion and mechanical methods, in combination with bone marrow mesenchymal stem cells of Wistar rats cultured in vitro, to repair 15 mm sciatic bone defects in Wistar rats. At postoperative 12 weeks, electrophysiological detection results showed that the conduction velocity of regenerated nerve after repair with tissue-engineered nerves was similar to that after autologous nerve grafting, and was higher than that after repair with acellular nerve allografts. Immunohistochemical staining revealed that motor endplates with acetylcholinesterase-positive nerve fibers were orderly arranged in the middle and superior parts of the gastrocnemius muscle; regenerated nerve tracts and sprouted branches were connected with motor endplates, as shown by acetylcholinesterase histochemistry combined with silver staining. The wet weight ratio of the tibialis anterior muscle at the affected contralateral hind limb was similar to the sciatic nerve after repair with autologous nerve grafts, and higher than that after repair with acellular nerve allografts. The hind limb motor function at the affected side was significantly improved, indicating that acellular nerve allografts combined with bone marrow mesenchymal stem cell bridging could promote functional recovery of rats with sciatic nerve defects. PMID:25206507

  9. Angular displacement measuring device

    NASA Technical Reports Server (NTRS)

    Seegmiller, H. Lee B. (inventor)

    1992-01-01

    A system for measuring the angular displacement of a point of interest on a structure, such as aircraft model within a wind tunnel, includes a source of polarized light located at the point of interest. A remote detector arrangement detects the orientation of the plane of the polarized light received from the source and compares this orientation with the initial orientation to determine the amount or rate of angular displacement of the point of interest. The detector arrangement comprises a rotating polarizing filter and a dual filter and light detector unit. The latter unit comprises an inner aligned filter and photodetector assembly which is disposed relative to the periphery of the polarizer so as to receive polarized light passing the polarizing filter and an outer aligned filter and photodetector assembly which receives the polarized light directly, i.e., without passing through the polarizing filter. The purpose of the unit is to compensate for the effects of dust, fog and the like. A polarization preserving optical fiber conducts polarized light from a remote laser source to the point of interest.

  10. The measurement of gas spaces in the roots of aquatic plants — Archimedes revisited

    Microsoft Academic Search

    Mark Curran; Peter James; William G. Allaway

    1996-01-01

    The volume of gas space within the root systems of pot-grown mangrove plants was determined by three methods based on Archimedes' principle: pycnometry, measurement of the upthrust on the root system when immersed in water, and measurement of the volume of water displaced. The results obtained using the upthrust and displacement methods were highly consistent. Although individual estimates obtained by

  11. Using intact nerve to bridge peripheral nerve defects: an alternative to the use of nerve grafts.

    PubMed

    McCallister, W V; Cober, S R; Norman, A; Trumble, T E

    2001-03-01

    This preliminary study was conducted to determine whether a regenerating peripheral nerve in a rat model can use the epineurium of an intact nerve to bridge a nerve gap defect. To create the intact nerve bridge a 1-cm segment of the peroneal nerve is resected leaving a gap defect. The proximal and distal peroneal nerve stumps are sutured 1-cm apart, in an end-to-side fashion, to the epineurium of the intact tibial nerve. The following experimental groups were used (n = 12): group A, immediate primary repair of resected segment; group B, intact nerve bridge technique; group C, nerve autograft; and group D, gap in situ control. Evaluation 12 weeks after surgery included measurement of the tibialis anterior muscle contraction force, axonal counting, wet weight of the tibialis anterior muscle, and histologic examination. The results of this animal study support 3 main conclusions: regenerating axons can use the epineurium of an intact nerve to bridge a gap in nerve continuity; when using functional recovery to assess regeneration, there is no significant difference between standard nerve autografts and the intact nerve bridge technique; and based on histologic examination, the intact nerve bridge technique does not injure the intact tibial nerve used to bridge the gap defect. Taken together, the results of this preliminary animal study suggest that the intact nerve bridge technique may be a potential alternative to standard nerve autografts in appropriate circumstances. Further investigation in a higher animal model is warranted before considering clinical application of the intact nerve bridge technique. PMID:11279579

  12. 21 CFR 882.5275 - Nerve cuff.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...Neurological Therapeutic Devices § 882.5275 Nerve cuff. (a) Identification. A nerve cuff is a tubular silicone rubber sheath used to encase a nerve for aid in repairing the nerve (e.g., to prevent ingrowth of scar tissue)...

  13. 21 CFR 882.5275 - Nerve cuff.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...Neurological Therapeutic Devices § 882.5275 Nerve cuff. (a) Identification. A nerve cuff is a tubular silicone rubber sheath used to encase a nerve for aid in repairing the nerve (e.g., to prevent ingrowth of scar tissue)...

  14. 21 CFR 882.5275 - Nerve cuff.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...Neurological Therapeutic Devices § 882.5275 Nerve cuff. (a) Identification. A nerve cuff is a tubular silicone rubber sheath used to encase a nerve for aid in repairing the nerve (e.g., to prevent ingrowth of scar tissue)...

  15. 21 CFR 882.5275 - Nerve cuff.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...Neurological Therapeutic Devices § 882.5275 Nerve cuff. (a) Identification. A nerve cuff is a tubular silicone rubber sheath used to encase a nerve for aid in repairing the nerve (e.g., to prevent ingrowth of scar tissue)...

  16. 21 CFR 882.5275 - Nerve cuff.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...Neurological Therapeutic Devices § 882.5275 Nerve cuff. (a) Identification. A nerve cuff is a tubular silicone rubber sheath used to encase a nerve for aid in repairing the nerve (e.g., to prevent ingrowth of scar tissue)...

  17. Intraosseous radial nerve entrapment complicating total elbow revision

    Microsoft Academic Search

    Jason Zook; William G Ward

    2001-01-01

    A 43-year-old man underwent revision of a loose total elbow arthroplasty in 1995. The arthroplasty had been implanted 20 years previously for post-traumatic osteoarthritis after a gunshot wound complicated by permanent ulnar nerve palsy. The patient suffered a minimally displaced periprosthetic fracture 4 years after implantation that was treated closed. The patient subsequently developed severe loosening with bony dilation. During

  18. Malignant peripheral nerve sheath tumor of the cauda equina.

    PubMed

    Acharya, R; Bhalla, S; Sehgal, A D

    2001-06-01

    Only one case of malignant peripheral nerve sheath tumor (MPNST) affecting the cauda equina region has been reported earlier. A 32-year-old male with congenital multiple subcutaneous swellings presented with low back pain, progressive paraparesis and bladder-bowel dysfunction. Magnetic resonance imaging (MRI) demonstrated a heterogeneously enhancing intradural lesion at L2-L4. At operation, on opening the dura, multiple nodular, firm matted masses attached to the lumbosacral nerve roots were encountered. Peripheral lesions were partially excised. Histopathological exam revealed varied cellularity with necrosis and pleomorphic nuclei suggestive of MPNST. MRI features, pathophysiological characteristics and the literature are reviewed. PMID:11731882

  19. Displacement Parameter Inversion for a Novel Electromagnetic Underground Displacement Sensor

    PubMed Central

    Shentu, Nanying; Li, Qing; Li, Xiong; Tong, Renyuan; Shentu, Nankai; Jiang, Guoqing; Qiu, Guohua

    2014-01-01

    Underground displacement monitoring is an effective method to explore deep into rock and soil masses for execution of subsurface displacement measurements. It is not only an important means of geological hazards prediction and forecasting, but also a forefront, hot and sophisticated subject in current geological disaster monitoring. In previous research, the authors had designed a novel electromagnetic underground horizontal displacement sensor (called the H-type sensor) by combining basic electromagnetic induction principles with modern sensing techniques and established a mutual voltage measurement theoretical model called the Equation-based Equivalent Loop Approach (EELA). Based on that work, this paper presents an underground displacement inversion approach named “EELA forward modeling-approximate inversion method”. Combining the EELA forward simulation approach with the approximate optimization inversion theory, it can deduce the underground horizontal displacement through parameter inversion of the H-type sensor. Comprehensive and comparative studies have been conducted between the experimentally measured and theoretically inversed values of horizontal displacement under counterpart conditions. The results show when the measured horizontal displacements are in the 0–100 mm range, the horizontal displacement inversion discrepancy is generally tested to be less than 3 mm under varied tilt angles and initial axial distances conditions, which indicates that our proposed parameter inversion method can predict underground horizontal displacement measurements effectively and robustly for the H-type sensor and the technique is applicable for practical geo-engineering applications. PMID:24858960

  20. Displacement parameter inversion for a novel electromagnetic underground displacement sensor.

    PubMed

    Shentu, Nanying; Li, Qing; Li, Xiong; Tong, Renyuan; Shentu, Nankai; Jiang, Guoqing; Qiu, Guohua

    2014-01-01

    Underground displacement monitoring is an effective method to explore deep into rock and soil masses for execution of subsurface displacement measurements. It is not only an important means of geological hazards prediction and forecasting, but also a forefront, hot and sophisticated subject in current geological disaster monitoring. In previous research, the authors had designed a novel electromagnetic underground horizontal displacement sensor (called the H-type sensor) by combining basic electromagnetic induction principles with modern sensing techniques and established a mutual voltage measurement theoretical model called the Equation-based Equivalent Loop Approach (EELA). Based on that work, this paper presents an underground displacement inversion approach named "EELA forward modeling-approximate inversion method". Combining the EELA forward simulation approach with the approximate optimization inversion theory, it can deduce the underground horizontal displacement through parameter inversion of the H-type sensor. Comprehensive and comparative studies have been conducted between the experimentally measured and theoretically inversed values of horizontal displacement under counterpart conditions. The results show when the measured horizontal displacements are in the 0-100 mm range, the horizontal displacement inversion discrepancy is generally tested to be less than 3 mm under varied tilt angles and initial axial distances conditions, which indicates that our proposed parameter inversion method can predict underground horizontal displacement measurements effectively and robustly for the H-type sensor and the technique is applicable for practical geo-engineering applications. PMID:24858960

  1. Laryngeal nerve monitoring.

    PubMed

    Kartush, Jack M; Naumann, Ilka

    2014-09-01

    Intraoperative neurophysiological monitoring of the vagus and recurrent laryngeal nerves is increasingly used during thyroidectomy, parathyroidectomy, skull base surgery, and cervical discectomy with fusion. Monitoring can assist in nerve localization and in reducing the incidence of neural trauma. To be effective, however, monitoring must be correctly implemented and the results interpreted based on an in-depth understanding of technique and the surgical structures at risk. Because "poor monitoring is worse than no monitoring" all members of the surgical monitoring team must have training specific to laryngeal recording to maximize its benefit and minimize pitfalls. This publication will review pertinent anatomy and neurophysiology as well as technical and interpretative factors. PMID:25351033

  2. Coding of position by simultaneously recorded sensory neurones in the cat dorsal root ganglion

    PubMed Central

    Stein, R B; Weber, D J; Aoyagi, Y; Prochazka, A; Wagenaar, J B M; Shoham, S; Normann, R A

    2004-01-01

    Muscle, cutaneous and joint afferents continuously signal information about the position and movement of individual joints. How does the nervous system extract more global information, for example about the position of the foot in space? To study this question we used microelectrode arrays to record impulses simultaneously from up to 100 discriminable nerve cells in the L6 and L7 dorsal root ganglia (DRG) of the anaesthetized cat. When the hindlimb was displaced passively with a random trajectory, the firing rate of the neurones could be predicted from a linear sum of positions and velocities in Cartesian (x, y), polar or joint angular coordinates. The process could also be reversed to predict the kinematics of the limb from the firing rates of the neurones with an accuracy of 1–2 cm. Predictions of position and velocity could be combined to give an improved fit to limb position. Decoders trained using random movements successfully predicted cyclic movements and movements in which the limb was displaced from a central point to various positions in the periphery. A small number of highly informative neurones (6–8) could account for over 80% of the variance in position and a similar result was obtained in a realistic limb model. In conclusion, this work illustrates how populations of sensory receptors may encode a sense of limb position and how the firing of even a small number of neurones can be used to decode the position of the limb in space. PMID:15331686

  3. Prolonged nerve blockade delays the onset of neuropathic pain

    PubMed Central

    Shankarappa, Sahadev A.; Tsui, Jonathan H.; Kim, Kristine N.; Reznor, Gally; Dohlman, Jenny C.; Langer, Robert; Kohane, Daniel S.

    2012-01-01

    Aberrant neuronal activity in injured peripheral nerves is believed to be an important factor in the development of neuropathic pain. Pharmacological blockade of that activity has been shown to mitigate the onset of associated molecular events in the nervous system. However, results in preventing onset of pain behaviors by providing prolonged nerve blockade have been mixed. Furthermore, the experimental techniques used to date to provide that blockade were limited in clinical potential in that they would require surgical implantation. To address these issues, we have used liposomes (SDLs) containing saxitoxin (STX), a site 1 sodium channel blocker, and the glucocorticoid agonist dexamethasone to provide nerve blocks lasting ?1 wk from a single injection. This formulation is easily injected percutaneously. Animals undergoing spared nerve injury (SNI) developed mechanical allodynia in 1 wk; nerve blockade with a single dose of SDLs (duration of block 6.9 ± 1.2 d) delayed the onset of allodynia by 2 d. Treatment with three sequential SDL injections resulting in a nerve block duration of 18.1 ± 3.4 d delayed the onset of allodynia by 1 mo. This very prolonged blockade decreased activation of astrocytes in the lumbar dorsal horn of the spinal cord due to SNI. Changes in expression of injury-related genes due to SNI in the dorsal root ganglia were not affected by SDLs. These findings suggest that formulations of this kind, which could be easy to apply clinically, can mitigate the development of neuropathic pain. PMID:23045676

  4. A Case of Hemifacial Spasm Caused by an Artery Passing Through the Facial Nerve

    PubMed Central

    Oh, Chang Hyun; Shim, Yu Shik; Park, Hyeonseon

    2015-01-01

    Hemifacial spasm (HFS) is a clinical syndrome characterized by unilateral facial nerve dysfunction. The usual cause involves vascular compression of the seventh cranial nerve, but compression by an artery passing through the facial nerve is very unusual. A 20-year-old man presented with left facial spasm that had persisted for 4 years. Compression of the left facial nerve root exit zone by the anterior inferior cerebellar artery (AICA) was revealed on magnetic resonance angiography. During microvascular decompression surgery, penetration of the distal portion of the facial nerve root exit zone by the AICA was observed. At the penetrating site, the artery was found to have compressed the facial nerve and to be immobilized. The penetrated seventh cranial nerve was longitudinally split about 2 mm. The compressing artery was moved away from the penetrating site and the decompression was secured by inserting Teflon at the operative site. Although the facial spasm disappeared in the immediate postoperative period, the patient continued to show moderate facial weakness. At postoperative 12 months, the facial weakness had improved to a mild degree. Prior to performing microvascular decompression of HFS, surgeons should be aware of a possibility for rare complex anatomy, such as compression by an artery passing through the facial nerve, which cannot be observed by modern imaging techniques. PMID:25810866

  5. A case of hemifacial spasm caused by an artery passing through the facial nerve.

    PubMed

    Oh, Chang Hyun; Shim, Yu Shik; Park, Hyeonseon; Kim, Eun-Young

    2015-03-01

    Hemifacial spasm (HFS) is a clinical syndrome characterized by unilateral facial nerve dysfunction. The usual cause involves vascular compression of the seventh cranial nerve, but compression by an artery passing through the facial nerve is very unusual. A 20-year-old man presented with left facial spasm that had persisted for 4 years. Compression of the left facial nerve root exit zone by the anterior inferior cerebellar artery (AICA) was revealed on magnetic resonance angiography. During microvascular decompression surgery, penetration of the distal portion of the facial nerve root exit zone by the AICA was observed. At the penetrating site, the artery was found to have compressed the facial nerve and to be immobilized. The penetrated seventh cranial nerve was longitudinally split about 2 mm. The compressing artery was moved away from the penetrating site and the decompression was secured by inserting Teflon at the operative site. Although the facial spasm disappeared in the immediate postoperative period, the patient continued to show moderate facial weakness. At postoperative 12 months, the facial weakness had improved to a mild degree. Prior to performing microvascular decompression of HFS, surgeons should be aware of a possibility for rare complex anatomy, such as compression by an artery passing through the facial nerve, which cannot be observed by modern imaging techniques. PMID:25810866

  6. Vestibular nerve section.

    PubMed

    Silverstein, Herbert; Jackson, Lance E

    2002-06-01

    When the vertigo of Meniere's disease becomes refractory to medical management, a variety of surgical options are available. If intratympanic gentamicin has failed or is not recommended and serviceable hearing is present, sectioning the vestibular nerve is an excellent option in terms of vertigo control, hearing preservation, and postoperative quality of life. Transection of the vestibular nerve has gone through a metamorphosis since attempted by Krause over a century ago. The microsurgical posterior fossa vestibular neurectomy has undergone an evolution, resulting in the combined RRVN. This is essentially a retrosigmoid approach with exposure of the lateral venous sinus to allow forward retraction of the sinus and better exposure. This technique has the advantages of minimization of required mastoid and suboccipital bone work, elimination of the need for cerebellar retraction, improved exposure, ability to achieve watertight dural closure to minimize incidence of CSF leakage, low incidence of postoperative headache, and low overall complication rate. If a cleavage plain cannot be readily identified, then the superior half of the eighth nerve is sectioned near the brainstem. The results are essentially the same whether the vestibular nerve is cut in the IAC or the posterior fossa. Vertigo has been completely controlled in 85% and hearing has been preserved at the preoperative level in 80% of patients. Combined RRVN is a direct and safe technique, with high success in properly selected patients. PMID:12486846

  7. Ischemic Nerve Block.

    ERIC Educational Resources Information Center

    Williams, Ian D.

    This experiment investigated the capability for movement and muscle spindle function at successive stages during the development of ischemic nerve block (INB) by pressure cuff. Two male subjects were observed under six randomly ordered conditions. The duration of index finger oscillation to exhaustion, paced at 1.2Hz., was observed on separate…

  8. Cervical Radiculopathy (Pinched Nerve)

    MedlinePLUS

    ... sometimes referred to as a “pinched” nerve. The medical term for this condition is cervical radiculopathy. Understanding your ... worn for short periods of time, because long-term wear can decrease the strength of neck ... and is not intended to serve as medical advice. Anyone seeking speci? c orthopaedic advice or ...

  9. Human amniotic epithelial cell transplantation for the repair of injured brachial plexus nerve: evaluation of nerve viscoelastic properties

    PubMed Central

    Jin, Hua; Yang, Qi; Ji, Feng; Zhang, Ya-jie; Zhao, Yan; Luo, Min

    2015-01-01

    The transplantation of embryonic stem cells can effectively improve the creeping strength of nerves near an injury site in animals. Amniotic epithelial cells have similar biological properties as embryonic stem cells; therefore, we hypothesized that transplantation of amniotic epithelial cells can repair peripheral nerve injury and recover the creeping strength of the brachial plexus nerve. In the present study, a brachial plexus injury model was established in rabbits using the C6 root avulsion method. A suspension of human amniotic epithelial cells was repeatedly injected over an area 4.0 mm lateral to the cephal and caudal ends of the C6 brachial plexus injury site (1 × 106 cells/mL, 3 ?L/injection, 25 injections) immediately after the injury. The results showed that the decrease in stress and increase in strain at 7,200 seconds in the injured rabbit C6 brachial plexus nerve were mitigated by the cell transplantation, restoring the viscoelastic stress relaxation and creep properties of the brachial plexus nerve. The forepaw functions were also significantly improved at 26 weeks after injury. These data indicate that transplantation of human amniotic epithelial cells can effectively restore the mechanical properties of the brachial plexus nerve after injury in rabbits and that viscoelasticity may be an important index for the evaluation of brachial plexus injury in animals.

  10. Human amniotic epithelial cell transplantation for the repair of injured brachial plexus nerve: evaluation of nerve viscoelastic properties.

    PubMed

    Jin, Hua; Yang, Qi; Ji, Feng; Zhang, Ya-Jie; Zhao, Yan; Luo, Min

    2015-02-01

    The transplantation of embryonic stem cells can effectively improve the creeping strength of nerves near an injury site in animals. Amniotic epithelial cells have similar biological properties as embryonic stem cells; therefore, we hypothesized that transplantation of amniotic epithelial cells can repair peripheral nerve injury and recover the creeping strength of the brachial plexus nerve. In the present study, a brachial plexus injury model was established in rabbits using the C6 root avulsion method. A suspension of human amniotic epithelial cells was repeatedly injected over an area 4.0 mm lateral to the cephal and caudal ends of the C6 brachial plexus injury site (1 × 10(6) cells/mL, 3 ?L/injection, 25 injections) immediately after the injury. The results showed that the decrease in stress and increase in strain at 7,200 seconds in the injured rabbit C6 brachial plexus nerve were mitigated by the cell transplantation, restoring the viscoelastic stress relaxation and creep properties of the brachial plexus nerve. The forepaw functions were also significantly improved at 26 weeks after injury. These data indicate that transplantation of human amniotic epithelial cells can effectively restore the mechanical properties of the brachial plexus nerve after injury in rabbits and that viscoelasticity may be an important index for the evaluation of brachial plexus injury in animals. PMID:25883625

  11. Segmental thoracic lipomatosis of nerve with nerve territory overgrowth.

    PubMed

    Mahan, Mark A; Amrami, Kimberly K; Howe, B Matthew; Spinner, Robert J

    2014-05-01

    Lipomatosis of nerve (LN), or fibrolipomatous hamartoma, is a rare condition of fibrofatty enlargement of the peripheral nerves. It is associated with bony and soft tissue overgrowth in approximately one-third to two-thirds of cases. It most commonly affects the median nerve at the carpal tunnel or digital nerves in the hands and feet. The authors describe a patient with previously diagnosed hemihypertrophy of the trunk who had a history of large thoracic lipomas resected during infancy, a thoracic hump due to adipose proliferation within the thoracic paraspinal musculature, and scoliotic deformity. She had fatty infiltration in the thoracic spinal nerves on MRI, identical to findings pathognomonic of LN at better-known sites. Enlargement of the transverse processes at those levels and thickened ribs were also found. This case appears to be directly analogous to other instances of LN with overgrowth, except that this case involved axial nerves rather than the typical appendicular nerves. PMID:24506247

  12. [Long term depression of the recurrent inhibition of monosynaptic spinal reflexes after sciatic nerve crush in adult rats].

    PubMed

    Shu, Liang; Dong, You-Rong; Yan, Wei-Hong; Zhai, Yu; Wang, Yun; Li, Wei

    2011-08-25

    Sciatic nerve injury is a common disease of peripheral nerve in clinic. After nerve injury, there are many dysfunctions in motoneurons and muscles following regeneration. Previous studies mostly investigated the aspects related to the injured nerve, and the effect on the recurrent inhibition (RI) pathway of spine following regeneration was not fully understood. Following reinnervation after temporary sciatic nerve crush, the functional alteration of RI was studied. In adult rats, RI between lateral gastrocnemius-soleus (LG-S) and medial gastrocnemius (MG) motor pools was assessed by conditioning monosynaptic reflexes (MSRs) elicited from the cut dorsal roots and recorded from either the LG-S or MG nerves by antidromic stimulation of the synergist muscle nerve. The following results were obtained. (1) The RI of MSRs in rats was almost lost (<5 weeks) after sciatic nerve crush. Although the RI partially recovered following reinnervation (6 weeks), it remained permanently depressed (up to 14 weeks). (2) Sciatic nerve crush on one side did not affect the contralateral RI. (3) Sciatic nerve crush did not induce any motoneuron loss revealed by immunohistochemistry. Peripheral nerve temporary disconnection causes long term alterations in RI pathway which make up motoneuron's function enhance for the alteration of muscle power and suggests that peripheral nerve injury induces long term plastic changes in the spinal motoneuron circuitry. PMID:21861046

  13. TPCP: Armillaria Root Rot ARMILLARIA ROOT ROT

    E-print Network

    TPCP: Armillaria Root Rot ARMILLARIA ROOT ROT INTRODUCTION A sometimes devastating root rot fungus. Armillaria root rot usually becomes apparent when indigenous forests are cleared for afforestation large indigenous trees In forestry situations, Armillaria root rot has been recorded on both pines

  14. Displacement, Substitution, Sublimation: A Bibliography.

    ERIC Educational Resources Information Center

    Pedrini, D. T.; Pedrini, Bonnie C.

    Sigmund Freund worked with the mechanisms of displacement, substitution, and sublimation. These mechanisms have many similarities and have been studied diagnostically and therapeutically. Displacement and substitution seem to fit in well with phobias, hysterias, somatiyations, prejudices, and scapegoating. Phobias, prejudices, and scapegoating…

  15. CHARACTER DISPLACEMENT IN POLYPHENIC TADPOLES

    Microsoft Academic Search

    David W. Pfennig; Peter J. Murphy

    2000-01-01

    Biologists have long known that closely related species are often phenotypically different where they occur together, but are indistinguishable where they occur alone. The causes of such character displacement are controversial, however. We used polyphenic spadefoot toad tadpoles (Spea bombifrons and S. multiplicata) to test the hypothesis that character displacement evolves to minimize competition for food. We also sought to

  16. Worker Displacement, 1995-97

    NSDL National Science Digital Library

    Thirty-three million workers were displaced from jobs they had held for at least three years, from January 1997 through December 1999. This number is roughly equivalent to the level of job losses covered in a survey that measured worker displacement from January 1995 through December 1997.

  17. Deficiency in monocarboxylate transporter 1 (MCT1) in mice delays regeneration of peripheral nerves following sciatic nerve crush.

    PubMed

    Morrison, Brett M; Tsingalia, Akivaga; Vidensky, Svetlana; Lee, Youngjin; Jin, Lin; Farah, Mohamed H; Lengacher, Sylvain; Magistretti, Pierre J; Pellerin, Luc; Rothstein, Jeffrey D

    2015-01-01

    Peripheral nerve regeneration following injury occurs spontaneously, but many of the processes require metabolic energy. The mechanism of energy supply to axons has not previously been determined. In the central nervous system, monocarboxylate transporter 1 (MCT1), expressed in oligodendroglia, is critical for supplying lactate or other energy metabolites to axons. In the current study, MCT1 is shown to localize within the peripheral nervous system to perineurial cells, dorsal root ganglion neurons, and Schwann cells by MCT1 immunofluorescence in wild-type mice and tdTomato fluorescence in MCT1 BAC reporter mice. To investigate whether MCT1 is necessary for peripheral nerve regeneration, sciatic nerves of MCT1 heterozygous null mice are crushed and peripheral nerve regeneration was quantified electrophysiologically and anatomically. Compound muscle action potential (CMAP) recovery is delayed from a median of 21 days in wild-type mice to greater than 38 days in MCT1 heterozygote null mice. In fact, half of the MCT1 heterozygote null mice have no recovery of CMAP at 42 days, while all of the wild-type mice recovered. In addition, muscle fibers remain 40% more atrophic and neuromuscular junctions 40% more denervated at 42 days post-crush in the MCT1 heterozygote null mice than wild-type mice. The delay in nerve regeneration is not only in motor axons, as the number of regenerated axons in the sural sensory nerve of MCT1 heterozygote null mice at 4 weeks and tibial mixed sensory and motor nerve at 3 weeks is also significantly reduced compared to wild-type mice. This delay in regeneration may be partly due to failed Schwann cell function, as there is reduced early phagocytosis of myelin debris and remyelination of axon segments. These data for the first time demonstrate that MCT1 is critical for regeneration of both sensory and motor axons in mice following sciatic nerve crush. PMID:25447940

  18. Acupuncture Treatment for Low Back Pain and Lower Limb Symptoms-The Relation between Acupuncture or Electroacupuncture Stimulation and Sciatic Nerve Blood Flow.

    PubMed

    Inoue, Motohiro; Kitakoji, Hiroshi; Yano, Tadashi; Ishizaki, Naoto; Itoi, Megumi; Katsumi, Yasukazu

    2008-06-01

    To investigate the clinical efficacy of acupuncture treatment for lumbar spinal canal stenosis and herniated lumbar disc and to clarify the mechanisms in an animal experiment that evaluated acupuncture on sciatic nerve blood flow. In the clinical trial, patients with lumbar spinal canal stenosis or herniated lumbar disc were divided into three treatment groups; (i) Ex-B2 (at the disordered level), (ii) electrical acupuncture (EA) on the pudendal nerve and (iii) EA at the nerve root. Primary outcome measurements were pain and dysesthesia [evaluated with a visual analogue scale (VAS)] and continuous walking distance. In the animal study, sciatic nerve blood flow was measured with laser-Doppler flowmetry at, before and during three kinds of stimulation (manual acupuncture on lumber muscle, electrical stimulation on the pudendal nerve and electrical stimulation on the sciatic nerve) in anesthetized rats. For the clinical trial, approximately half of the patients who received Ex-B2 revealed amelioration of the symptoms. EA on the pudendal nerve was effective for the symptoms which had not improved by Ex-B2. Considerable immediate and sustained relief was observed in patients who received EA at the nerve root. For the animal study, increase in sciatic nerve blood flow was observed in 56.9% of the trial with lumber muscle acupuncture, 100% with pudendal nerve stimulation and 100% with sciatic nerve stimulation. Sciatic nerve stimulation sustained the increase longer than pudendal nerve stimulation. One mechanism of action of acupuncture and electrical acupuncture stimulation could be that, in addition to its influence on the pain inhibitory system, it participates in causing a transient change in sciatic nerve blood blow, including circulation to the cauda equine and nerve root. PMID:18604251

  19. Artemin induced functional recovery and reinnervation after partial nerve injury.

    PubMed

    Wang, Ruizhong; Rossomando, Anthony; Sah, Dinah W Y; Ossipov, Michael H; King, Tamara; Porreca, Frank

    2014-03-01

    Systemic artemin promotes regeneration of dorsal roots to the spinal cord after crush injury. However, it is unclear whether systemic artemin can also promote peripheral nerve regeneration, and functional recovery after partial lesions distal to the dorsal root ganglion (DRG) remains unknown. In the present investigation, male Sprague Dawley rats received axotomy, ligation, or crush of the L5 spinal nerve or sham surgery. Starting the day of injury, animals received intermittent subcutaneous artemin or vehicle across 2weeks. Sensory thresholds to tactile or thermal stimuli were monitored for 6weeks after injury. Immunohistochemical analyses of the DRG and nerve regeneration were performed at the 6-week time point. Artemin transiently reversed tactile and thermal hypersensitivity after axotomy, ligation, or crush injury. Thermal and tactile hypersensitivity reemerged within 1week of treatment termination. However, artemin-treated rats with nerve crush, but not axotomy or ligation, subsequently showed gradual return of sensory thresholds to preinjury baseline levels by 6weeks after injury. Artemin normalized labeling for NF200, IB4, and CGRP in nerve fibers distal to the crush injury, suggesting persistent normalization of nerve crush-induced neurochemical changes. Sciatic and intradermal administration of dextran or cholera toxin B distal to the crush injury site resulted in labeling of neuronal profiles in the L5 DRG, suggesting regeneration functional restoration of nonmyelinated and myelinated fibers across the injury site into cutaneous tissue. Artemin also diminished ATF3 and caspase 3 expression in the L5 DRG, suggesting persistent neuroprotective actions. A limited period of artemin treatment elicits disease modification by promoting sensory reinnervation of distal territories and restoring preinjury sensory thresholds. PMID:24269493

  20. Peripheral nerve sheath tumor in a subadult golden eagle (Aquila chrysaetos).

    PubMed

    Wernick, Morena Bernadette; Dennler, Matthias; Beckmann, Kathrin; Schybli, Martina; Albini, Sarah; Hoop, Richard K; Steffen, Frank; Kircher, Patrick; Hatt, Jean-Michel

    2014-03-01

    A 5-year-old, female golden eagle (Aquila chrysaetos) was admitted with tetraplegia that progressed to a nonambulatory, spastic tetraparesis after a few days of treatment. Clinical and radiologic examinations, including radiography, computed tomography scan, and myelography, were indicative of neoplasia involving a spinal nerve root. Postmortem magnetic resonance imaging and necropsy findings confirmed the diagnosis of a peripheral nerve sheath neoplasia, not, to our knowledge, previously reported in a raptor. PMID:24881155

  1. Ultrasound of Peripheral Nerves

    PubMed Central

    Suk, Jung Im; Walker, Francis O.; Cartwright, Michael S.

    2013-01-01

    Over the last decade, neuromuscular ultrasound has emerged as a useful tool for the diagnosis of peripheral nerve disorders. This article reviews sonographic findings of normal nerves including key quantitative ultrasound measurements that are helpful in the evaluation of focal and possibly generalized peripheral neuropathies. It also discusses several recent papers outlining the evidence base for the use of this technology, as well as new findings in compressive, traumatic, and generalized neuropathies. Ultrasound is well suited for use in electrodiagnostic laboratories where physicians, experienced in both the clinical evaluation of patients and the application of hands-on technology, can integrate findings from the patient’s history, physical examination, electrophysiological studies, and imaging for diagnosis and management. PMID:23314937

  2. Nerves in a pinch: imaging of nerve compression syndromes.

    PubMed

    Hochman, Mary G; Zilberfarb, Jeffrey L

    2004-01-01

    Nerve compression is a common entity that can result in considerable disability. Early diagnosis is important to institute prompt treatment and to minimize potential injury. Although the appropriate diagnosis is often determined by clinical examination, the diagnosis may be more difficult when the presentation is atypical, or when anatomic and technical limitations intervene. In these instances, imaging can have an important role in helping to define the site and etiology of nerve compression or in establishing an alternative diagnosis. MR imaging and ultrasound provide direct visualization of the nerve and surrounding abnormalities. For both modalities, the use of high-resolution techniques is important. Bony abnormalities contributing to nerve compression are best assessed by radiographs or CT. For the radiologist, knowledge of the anatomy of the fibro-osseous tunnels, familiarity with the causes of nerve compression, and an understanding of specialized imaging techniques are important for successful diagnosis of nerve compression. PMID:15049533

  3. Optic nerve hypoplasia.

    PubMed

    Kaur, Savleen; Jain, Sparshi; Sodhi, Harsimrat B S; Rastogi, Anju; Kamlesh

    2013-05-01

    Optic nerve hypoplasia (ONH) is a congenital anomaly of the optic disc that might result in moderate to severe vision loss in children. With a vast number of cases now being reported, the rarity of ONH is obviously now refuted. The major aspects of ophthalmic evaluation of an infant with possible ONH are visual assessment, fundus examination, and visual electrophysiology. Characteristically, the disc is small, there is a peripapillary double-ring sign, vascular tortuosity, and thinning of the nerve fiber layer. A patient with ONH should be assessed for presence of neurologic, radiologic, and endocrine associations. There may be maternal associations like premature births, fetal alcohol syndrome, maternal diabetes. Systemic associations in the child include endocrine abnormalities, developmental delay, cerebral palsy, and seizures. Besides the hypoplastic optic nerve and chiasm, neuroimaging shows abnormalities in ventricles or white- or gray-matter development, septo-optic dysplasia, hydrocephalus, and corpus callosum abnormalities. There is a greater incidence of clinical neurologic abnormalities in patients with bilateral ONH (65%) than patients with unilateral ONH. We present a review on the available literature on the same to urge caution in our clinical practice when dealing with patients with ONH. Fundus photography, ocular coherence tomography, visual field testing, color vision evaluation, neuroimaging, endocrinology consultation with or without genetic testing are helpful in the diagnosis and management of ONH. (Method of search: MEDLINE, PUBMED). PMID:24082663

  4. Optic nerve hypoplasia

    PubMed Central

    Kaur, Savleen; Jain, Sparshi; Sodhi, Harsimrat B. S.; Rastogi, Anju; Kamlesh

    2013-01-01

    Optic nerve hypoplasia (ONH) is a congenital anomaly of the optic disc that might result in moderate to severe vision loss in children. With a vast number of cases now being reported, the rarity of ONH is obviously now refuted. The major aspects of ophthalmic evaluation of an infant with possible ONH are visual assessment, fundus examination, and visual electrophysiology. Characteristically, the disc is small, there is a peripapillary double-ring sign, vascular tortuosity, and thinning of the nerve fiber layer. A patient with ONH should be assessed for presence of neurologic, radiologic, and endocrine associations. There may be maternal associations like premature births, fetal alcohol syndrome, maternal diabetes. Systemic associations in the child include endocrine abnormalities, developmental delay, cerebral palsy, and seizures. Besides the hypoplastic optic nerve and chiasm, neuroimaging shows abnormalities in ventricles or white- or gray-matter development, septo-optic dysplasia, hydrocephalus, and corpus callosum abnormalities. There is a greater incidence of clinical neurologic abnormalities in patients with bilateral ONH (65%) than patients with unilateral ONH. We present a review on the available literature on the same to urge caution in our clinical practice when dealing with patients with ONH. Fundus photography, ocular coherence tomography, visual field testing, color vision evaluation, neuroimaging, endocrinology consultation with or without genetic testing are helpful in the diagnosis and management of ONH. (Method of search: MEDLINE, PUBMED). PMID:24082663

  5. Lower extremity nerve blocks.

    PubMed

    Dilger, J A

    2000-06-01

    Lower extremity nerve blocks have not become as popular as upper extremity blocks for anesthesia; however, the use of lower extremity nerve blocks will become more widespread, as teaching programs are now providing more regional anesthesia experiences for their trainees so that the anesthesia provider will have the familiarity to use these blocks. To increase the enthusiasm among our surgical colleagues, we must begin to use these blocks for surgery, and if the block must be supplemented with local anesthetic or a light general anesthetic, we must educate them that the block is not a failure but a success, as it will provide analgesia after surgery in a method of multimodal pain control. Lower extremity nerve blocks will become more popular when it is realized that they are an effective way of increasing operating room efficiency. Because the block may be placed in an induction room, there is no induction or emergence in the operating room. Patients may be discharged without the need for pain medications, thus lowering the incidence of nausea postoperatively and decreasing PACU and discharge times. PMID:10935013

  6. Peripheral nerve hyperexcitability syndromes.

    PubMed

    Küçükali, Cem Ismail; Kürtüncü, Murat; Akçay, Halil ?brahim; Tüzün, Erdem; Öge, Ali Emre

    2015-01-01

    Peripheral nerve hyperexcitability (PNH) syndromes can be subclassified as primary and secondary. The main primary PNH syndromes are neuromyotonia, cramp-fasciculation syndrome (CFS), and Morvan's syndrome, which cause widespread symptoms and signs without the association of an evident peripheral nerve disease. Their major symptoms are muscle twitching and stiffness, which differ only in severity between neuromyotonia and CFS. Cramps, pseudomyotonia, hyperhidrosis, and some other autonomic abnormalities, as well as mild positive sensory phenomena, can be seen in several patients. Symptoms reflecting the involvement of the central nervous system occur in Morvan's syndrome. Secondary PNH syndromes are generally seen in patients with focal or diffuse diseases affecting the peripheral nervous system. The PNH-related symptoms and signs are generally found incidentally during clinical or electrodiagnostic examinations. The electrophysiological findings that are very useful in the diagnosis of PNH are myokymic and neuromyotonic discharges in needle electromyography along with some additional indicators of increased nerve fiber excitability. Based on clinicopathological and etiological associations, PNH syndromes can also be classified as immune mediated, genetic, and those caused by other miscellaneous factors. There has been an increasing awareness on the role of voltage-gated potassium channel complex autoimmunity in primary PNH pathogenesis. Then again, a long list of toxic compounds and genetic factors has also been implicated in development of PNH. The management of primary PNH syndromes comprises symptomatic treatment with anticonvulsant drugs, immune modulation if necessary, and treatment of possible associated dysimmune and/or malignant conditions. PMID:25719304

  7. Regenerative rotary displacer Stirling engine

    SciTech Connect

    Isshiki, Naotsugu; Watanabe, Hiroichi [Nihon Univ. Tokyo (Japan); Raggi, L. [Waseda Univ., Tokyo (Japan); Isshiki, Seita; Hirata, Koichi

    1996-12-31

    A few rotary displacer Stirling engines in which the displacer has one gas pocket space at one side and rotates in a main enclosed cylinder, which is heated from one side and cooled from opposite side without any regenerator, have been studied for some time by the authors. The authors tried to improve this engine by equipping it with a regenerator, because without a regenerator, pressure oscillation and efficiency are too small. Here, several types of regenerative rotary displacer piston Stirling engines are proposed. One is the contra-rotating tandem two disc type displacer engine using axial heat conduction through side walls or by heat pipes and another is a single disc type with circulating fluid regenerator or heat pipes. Stirling engines of this new rotary displacer type are thought to attain high speed. Here, experimental results of the original rotary displacer Stirling engine without a regenerator, and one contra-rotating tandem displacer engine with side wall regenerator by axial heat conduction are reported accompanied with a discussion of the results.

  8. Borehole optical lateral displacement sensor

    DOEpatents

    Lewis, R.E.

    1998-10-20

    There is provided by this invention an optical displacement sensor that utilizes a reflective target connected to a surface to be monitored to reflect light from a light source such that the reflected light is received by a photoelectric transducer. The electric signal from the photoelectric transducer is then imputed into electronic circuitry to generate an electronic image of the target. The target`s image is monitored to determine the quantity and direction of any lateral displacement in the target`s image which represents lateral displacement in the surface being monitored. 4 figs.

  9. Robotic excision of a pre-coccygeal nerve root tumor.

    PubMed

    Palep, Jaydeep H; Mistry, Sheetal; Kumar, Abhaya; Munshi, Mihir; Puranik, Meenakshi; Pednekar, Abhinav

    2015-01-01

    Pre-coccygeal ganglioneuroma is a rare clinical entity that presents incidentally or with non-specific symptoms. We present a case of a 25 year old housewife who was incidentally diagnosed with pre-coccygeal ganglioneuroma while getting investigated for primary infertility. The patient had no specific complaints except for irregular menstruation which had started 8 months back. Magnetic resonance imaging (MRI) was suggestive of a presacral and pre-coccygeal lesion. Resection of the tumor was done through the anterior approach using the da Vinci Si robotic system. Two robotic arms and one assistant port were used to completely excise the tumor. Robotic excision of such a tumor mass located at a relatively inaccessible area allows enhanced precision and 3-dimentional (3D) view avoiding damage to important surrounding structures. PMID:25598609

  10. Extramedullary hematopoietic tumor mimicking a thoracic nerve root schwannoma.

    PubMed

    Oermann, Eric K; Coppa, Nicholas D; Margolis, Marc; Sandhu, Faheem A

    2010-07-01

    Extramedullary hematopoiesis secondary to chronic anemia is well reported throughout the literature. A rare presentation of this condition is in the central nervous tissue reported most frequently as an epidural mass causing spinal cord compression. The authors report the case of a 51-year-old man with beta-thalassemia and chronic anemia who was found to have a 4-cm paravertebral mass suggestive of a schwannoma. The patient underwent transthoracic resection of the mass. Histological examination confirmed an extramedullary hematopoietic tumor. In this article the authors propose a method to distinguish extramedullary hematopoietic tumors from schwannomas. To the authors' knowledge, this is the first reported case in the neurosurgical literature of this phenomenon. PMID:20594021

  11. Sixth cranial nerve palsy caused by compression from a dolichoectatic vertebral artery.

    PubMed

    Zhu, Ying; Thulborn, Keith; Curnyn, Kimberlee; Goodwin, James

    2005-06-01

    A 68-year-old man had an unremitting left sixth cranial nerve palsy immediately after completing a long bicycle trip. High-resolution (3 Tesla) magnetic resonance imaging disclosed a dolichoectatic vertebral artery that compressed the left sixth cranial nerve against the belly of the pons at its root exit zone. It was postulated that increased blood flow in the vessel during the unusually prolonged aerobic exercise precipitated the palsy. Compressive palsies of cranial nerves caused by a dolichoectatic basilar artery have often been documented; compressive palsy caused by a dolichoectatic vertebral artery is less well-recognized. PMID:15937439

  12. Neuromuscular Ultrasound of Cranial Nerves

    PubMed Central

    Tawfik, Eman A.; Cartwright, Michael S.

    2015-01-01

    Ultrasound of cranial nerves is a novel subdomain of neuromuscular ultrasound (NMUS) which may provide additional value in the assessment of cranial nerves in different neuromuscular disorders. Whilst NMUS of peripheral nerves has been studied, NMUS of cranial nerves is considered in its initial stage of research, thus, there is a need to summarize the research results achieved to date. Detailed scanning protocols, which assist in mastery of the techniques, are briefly mentioned in the few reference textbooks available in the field. This review article focuses on ultrasound scanning techniques of the 4 accessible cranial nerves: optic, facial, vagus and spinal accessory nerves. The relevant literatures and potential future applications are discussed. PMID:25851889

  13. Reduced Renshaw Recurrent Inhibition after Neonatal Sciatic Nerve Crush in Rats

    PubMed Central

    Shu, Liang; Su, Jingjing; Jing, Lingyan; Huang, Ying; Di, Yu; Peng, Lichao; Liu, Jianren

    2014-01-01

    Renshaw recurrent inhibition (RI) plays an important gated role in spinal motion circuit. Peripheral nerve injury is a common disease in clinic. Our current research was designed to investigate the change of the recurrent inhibitory function in the spinal cord after the peripheral nerve crush injury in neonatal rat. Sciatic nerve crush was performed on 5-day-old rat puppies and the recurrent inhibition between lateral gastrocnemius-soleus (LG-S) and medial gastrocnemius (MG) motor pools was assessed by conditioning monosynaptic reflexes (MSR) elicited from the sectioned dorsal roots and recorded either from the LG-S and MG nerves by antidromic stimulation of the synergist muscle nerve. Our results demonstrated that the MSR recorded from both LG-S or MG nerves had larger amplitude and longer latency after neonatal sciatic nerve crush. The RI in both LG-S and MG motoneuron pools was significantly reduced to virtual loss (15–20% of the normal RI size) even after a long recovery period upto 30 weeks after nerve crush. Further, the degree of the RI reduction after tibial nerve crush was much less than that after sciatic nerve crush indicatig that the neuron-muscle disconnection time is vital to the recovery of the spinal neuronal circuit function during reinnervation. In addition, sciatic nerve crush injury did not cause any spinal motor neuron loss but severally damaged peripheral muscle structure and function. In conclusion, our results suggest that peripheral nerve injury during neonatal early development period would cause a more sever spinal cord inhibitory circuit damage, particularly to the Renshaw recurrent inhibition pathway, which might be the target of neuroregeneration therapy. PMID:24778886

  14. Displacement sensing system and method

    DOEpatents

    VunKannon Jr., Robert S

    2006-08-08

    A displacement sensing system and method addresses demanding requirements for high precision sensing of displacement of a shaft, for use typically in a linear electro-dynamic machine, having low failure rates over multi-year unattended operation in hostile environments. Applications include outer space travel by spacecraft having high-temperature, sealed environments without opportunity for servicing over many years of operation. The displacement sensing system uses a three coil sensor configuration, including a reference and sense coils, to provide a pair of ratio-metric signals, which are inputted into a synchronous comparison circuit, which is synchronously processed for a resultant displacement determination. The pair of ratio-metric signals are similarly affected by environmental conditions so that the comparison circuit is able to subtract or nullify environmental conditions that would otherwise cause changes in accuracy to occur.

  15. Literature Review of Displacement Ventilation

    E-print Network

    Cho, S.; Im, P.; Haberl, J. S.

    Performance Evaluation and Design Guidelines for Displacement Ventilation” by Chen and Clicksman (2003), were used to begin the literature search. Their references include papers, articles, and web sites presenting major contributions to the understanding...

  16. Population Displacements Associated with Environmentally

    E-print Network

    Columbia University

    associated with large infrastructure ­ Typology of displacements ­ Case Studies · Mali · Brazil · South to changing climate (drought flood­ Infrastructure in response to changing climate (drought, flood, disasters Socio economic Impacts Enviro Impacts Dam Climate Change Fresh H20 Salinization Drought Flood

  17. Polyimidazoles Via Aromatic Nucleophilic Displacement

    NASA Technical Reports Server (NTRS)

    Connell, John W.; Hergenrother, Paul M.

    1990-01-01

    Experiments show variety of polyimidazoles prepared by aromatic nucleophilic displacement, from reactions of bisphenol imidazoles with activated difluoro compounds. Polyimidazoles have good mechanical properties making them suitable for use as films, moldings, and adhesives.

  18. Pythium Root Rot (and Feeder Root Necrosis)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pythium species cause a number of diseases on corn. Among the Pythium diseases, root rot presents the least conspicuous aboveground symptoms. Broadly defined, root rot also includes feeder root necrosis. At least 16 species of Pythium are known to cause root rot of corn. These include P. acanthicu...

  19. Geometric Deformation-Displacement Maps

    Microsoft Academic Search

    Gershon Elber

    2002-01-01

    Texture mapping, bump mapping, and displacement maps are central instruments in computer graphics aiming to achieve photo-realistic renderings. In all these techniques, the mapping is typically one-to-one and a single surface location is assigned a single texture color, normal, or displacement. Other specialized techniques have also been developed for the rendering of supplementary surface details such as fur hair, or

  20. 40 CFR 205.153 - Engine displacement.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false Engine displacement. 205.153 Section 205.153 Protection...CONTROLS Motorcycles § 205.153 Engine displacement. (a) Engine displacement must be calculated using nominal...

  1. 40 CFR 205.153 - Engine displacement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Engine displacement. 205.153 Section 205.153 Protection...CONTROLS Motorcycles § 205.153 Engine displacement. (a) Engine displacement must be calculated using nominal...

  2. In vivo nerve-macrophage interactions following peripheral nerve injury

    PubMed Central

    Rosenberg, Allison; Wolman, Marc A.; Franzini-Armstrong, Clara; Granato, Michael

    2012-01-01

    In vertebrates, the peripheral nervous system has retained its regenerative capacity, enabling severed axons to reconnect with their original synaptic targets. While it is well documented that a favorable environment is critical for nerve regeneration, the complex cellular interactions between injured nerves with cells in their environment, as well as the functional significance of these interactions, have not been determined in vivo and in real time. Here we provide the first minute-by-minute account of cellular interactions between laser transected motor nerves and macrophages in live intact zebrafish. We show that macrophages arrive at the lesion site long before axon fragmentation, much earlier than previously thought. Moreover, we find that axon fragmentation triggers macrophage invasion into the nerve to engulf axonal debris, and that delaying nerve fragmentation in a Wlds model does not alter macrophage recruitment but induces a previously unknown ‘nerve scanning’ behavior, suggesting that macrophage recruitment and subsequent nerve invasion are controlled by separate mechanisms. Finally, we demonstrate that macrophage recruitment, thought to be dependent on Schwann cell derived signals, occurs independently of Schwann cells. Thus, live cell imaging defines novel cellular and functional interactions between injured nerves and immune cells. PMID:22423110

  3. Nerve-pulse interactions

    SciTech Connect

    Scott, A.C.

    1982-01-01

    Some recent experimental and theoretical results on mechanisms through which individual nerve pulses can interact are reviewed. Three modes of interactions are considered: (1) interaction of pulses as they travel along a single fiber which leads to velocity dispersion; (2) propagation of pairs of pulses through a branching region leading to quantum pulse code transformations; and (3) interaction of pulses on parallel fibers through which they may form a pulse assembly. This notion is analogous to Hebb's concept of a cell assembly, but on a lower level of the neural hierarchy.

  4. Nervous System, Neurons, Nerves

    NSDL National Science Digital Library

    How does the nervous system work? It is a question that has engaged the minds of scientists, doctors, and others for centuries. The National Science Teachers Association (NSTA) has created this tour of the nervous system for teachers and students. First-time visitors can start with the Explore a Nerve Cell area, which goes over the membrane, nucleus, axon, dendrites, and the synapse in exquisite detail with interactive graphics. Moving on, The Basics area provides summaries of the operation of the nervous system and a rather illustrative area named Ouch! The site is rounded out by the Nervous Systems Explorations section, which has some nice simulations covering Brainstorms and Simple Reflexes.

  5. Effects of nerve growth factor on nerve regeneration after corneal nerve damage

    PubMed Central

    Ma, Ke; Yan, Naihong; Huang, Yongzhi; Cao, Guiqun; Deng, Jie; Deng, Yingping

    2014-01-01

    The study aims to determine the relation between the effects of mouse nerve growth factor (mNGF) and nerve regeneration after corneal surgery nerve damage. Mechanical nerve injury animal model was established by LASIK (the excimer laser keratomileusis) surgery in 12 Belgian rabbits. mNGF and the balanced salt solution (BBS) were alternatively administered in the left and right eye two times every day for 8 weeks. The morphous and growth of the sub-basal nerve plexus and superficial stroma were observed by in vivo confocal microscopy at the end of weeks 1, 2, 4 and 8 after the surgery. The animal model is successfully established. The morphology and density of corneal nerve have been observed and demonstrated by confocal microscopy. A systematic administration of mNGF can significantly promote the nerve regeneration at the end of weeks 1, 2, 4 and 8, which comparing to the administration of balanced salt solution (P < 0.05). mNGF has effect on sub-basal nerve plexus and superficial stroma after corneal nerve damage which is caused by LASIK. The experimental results suggested that the mNGF may solve the problem of dry eye after LASIK. PMID:25550989

  6. Double gene therapy with granulocyte colony-stimulating factor and vascular endothelial growth factor acts synergistically to improve nerve regeneration and functional outcome after sciatic nerve injury in mice.

    PubMed

    Pereira Lopes, F R; Martin, P K M; Frattini, F; Biancalana, A; Almeida, F M; Tomaz, M A; Melo, P A; Borojevic, R; Han, S W; Martinez, A M B

    2013-01-29

    Peripheral-nerve injuries are a common clinical problem and often result in long-term functional deficits. Reconstruction of peripheral-nerve defects is currently undertaken with nerve autografts. However, there is a limited availability of nerves that can be sacrificed and the functional recovery is never 100% satisfactory. We have previously shown that gene therapy with vascular endothelial growth factor (VEGF) significantly improved nerve regeneration, neuronal survival, and muscle activity. Our hypothesis is that granulocyte colony-stimulating factor (G-CSF) synergizes with VEGF to improve the functional outcome after sciatic nerve transection. The left sciatic nerves and the adjacent muscle groups of adult mice were exposed, and 50 or 100 ?g (in 50 ?l PBS) of VEGF and/or G-CSF genes was injected locally, just below the sciatic nerve, and transferred by electroporation. The sciatic nerves were transected and placed in an empty polycaprolactone (PCL) nerve guide, leaving a 3-mm gap to challenge nerve regeneration. After 6 weeks, the mice were perfused and the sciatic nerve, the dorsal root ganglion (DRG), the spinal cord and the gastrocnemius muscle were processed for light and transmission electron microscopy. Treated animals showed significant improvement in functional and histological analyses compared with the control group. However, the best results were obtained with the G-CSF+VEGF-treated animals: quantitative analysis of regenerated nerves showed a significant increase in the number of myelinated fibers and blood vessels, and the number of neurons in the DRG and motoneurons in the spinal cord was significantly higher. Motor function also showed that functional recovery occurred earlier in animals receiving G-CSF+VEGF-treatment. The gastrocnemius muscle showed an increase in weight and in the levels of creatine phosphokinase, suggesting an improvement of reinnervation and muscle activity. These results suggest that these two factors acted synergistically and optimized the nerve repair potential, improving regeneration after a transection lesion. PMID:23103791

  7. Direct Evaluation of the Ca2+-Displacement Hypothesis for Al Toxicity.

    PubMed Central

    Ryan, P. R.; Reid, R. J.; Smith, F. A.

    1997-01-01

    One explanation for Al toxicity in plants suggests that Al displaces Ca2+ from critical sites in the apoplasm. We evaluated the Ca2+-displacement hypothesis directly using near-isogenic lines of wheat (Triticum aestivum L.) that differ in Al tolerance at a single locus. We measured both the growth and total accumulation (apoplasmic plus symplasmic) of 45Ca and Al into roots that had been exposed to Al alone or to Al with other cations. Root growth in the Al-sensitive line was found to be severely inhibited by low activities of Al, even though Ca2+ accumulation was relatively unaffected. In solutions containing the same activity of the Al3+ and Ca2+ ions as above, but also including either 3.0 mM Mg2+, 3.0 mM Sr2+, or 30 mM Na+, growth improved, whereas 45Ca2+ accumulation was significantly decreased. Since most of the 45Ca2+ accumulated by roots during short-term treatments will reside in the apoplasm, these results indicate that displacement of Ca2+ from the apoplasm by Al cannot account for the Al-induced inhibition of root growth and, therefore, do not support the Ca2+-displacement hypothesis for Al toxicity. We also show that total accumulation of Al by root apices is greater in the Al-sensitive genotype than the Al-tolerant genotype and suggest that cation amelioration of Al toxicity is caused by the reduction in Al accumulation. PMID:12223678

  8. Blade Displacement Predictions for the Full-Scale UH-60A Airloads Rotor

    NASA Technical Reports Server (NTRS)

    Bledron, Robert T.; Lee-Rausch, Elizabeth M.

    2014-01-01

    An unsteady Reynolds-Averaged Navier-Stokes solver for unstructured grids is loosely coupled to a rotorcraft comprehensive code and used to simulate two different test conditions from a wind-tunnel test of a full-scale UH-60A rotor. Performance data and sectional airloads from the simulation are compared with corresponding tunnel data to assess the level of fidelity of the aerodynamic aspects of the simulation. The focus then turns to a comparison of the blade displacements, both rigid (blade root) and elastic. Comparisons of computed root motions are made with data from three independent measurement systems. Finally, comparisons are made between computed elastic bending and elastic twist, and the corresponding measurements obtained from a photogrammetry system. Overall the correlation between computed and measured displacements was good, especially for the root pitch and lag motions and the elastic bending deformation. The correlation of root lead-lag motion and elastic twist deformation was less favorable.

  9. Restorative effect and mechanism of mecobalamin on sciatic nerve crush injury in mice

    PubMed Central

    Gan, Lin; Qian, Minquan; Shi, Keqin; Chen, Gang; Gu, Yanglin; Du, Wei; Zhu, Guoxing

    2014-01-01

    Mecobalamin, a form of vitamin B12 containing a central metal element (cobalt), is one of the most important mediators of nervous system function. In the clinic, it is often used to accelerate recovery of peripheral nerves, but its molecular mechanism remains unclear. In the present study, we performed sciatic nerve crush injury in mice, followed by daily intraperitoneal administration of mecobalamin (65 ?g/kg or 130 ?g/kg) or saline (negative control). Walking track analysis, histomorphological examination, and quantitative real-time PCR showed that mecobalamin significantly improved functional recovery of the sciatic nerve, thickened the myelin sheath in myelinated nerve fibers, and increased the cross-sectional area of target muscle cells. Furthermore, mecobalamin upregulated mRNA expression of growth associated protein 43 in nerve tissue ipsilateral to the injury, and of neurotrophic factors (nerve growth factor, brain-derived nerve growth factor and ciliary neurotrophic factor) in the L4–6 dorsal root ganglia. Our findings indicate that the molecular mechanism underlying the therapeutic effect of mecobalamin after sciatic nerve injury involves the upregulation of multiple neurotrophic factor genes. PMID:25598780

  10. Rehabilitation following motor nerve transfers.

    PubMed

    Novak, Christine B

    2008-11-01

    Cortical mapping and relearning are key factors in optimizing patient outcome following motor nerve transfers. To maximize function following nerve transfers, the rehabilitation program must include motor reeducation to initiate recruitment of the weak reinnervated muscles and to establish new motor patterns and cortical mapping. Patient education and a home program are essential to obtain the optimal functional result. PMID:18928890

  11. Neuromas of the calcaneal nerves.

    PubMed

    Kim, J; Dellon, A L

    2001-11-01

    A neuroma of a calcaneal nerve has never been reported. A series of 15 patients with heel pain due to a neuroma of a calcaneal nerve are reviewed. These patients previously had either a plantar fasciotomy (n = 4), calcaneal spur removal (n = 2), ankle fusion (n = 2), or tarsal tunnel decompression (n = 7). Neuromas occurred on calcaneal branches that arose from either the posterior tibial nerve (n = 1), lateral plantar nerve (n = 1), the medial plantar nerve (n = 9), or more than one of these nerves (n = 4). Operative approach was through an extended tarsal tunnel incision to permit identification of all calcaneal nerves. The neuroma was resected and implanted into the flexor hallucis longus muscle. Excellent relief of pain occurred in 60%, and good relief in 33%. One patient (17%) had no improvement and required resection of the lateral plantar nerve. Awareness that the heel may be innervated by multiple calcaneal branches suggests that surgery for heel pain of neural origin employ a surgical approach that permits identification of all possible calcaneal branches. PMID:11722141

  12. Temporal Adaptation Silicon Auditory Nerve

    E-print Network

    Lazzaro, John

    Temporal Adaptation in a Silicon Auditory Nerve John Lazzaro CS Division UC Berkeley 571 Evans Hall Berkeley, CA 94720 Abstract Many auditory theorists consider the temporal adaptation of the auditory nerve localization and pitch perception also suggest temporal adaptation is an important ele- ment of practical

  13. Peripheral nerve lengthening as a regenerative strategy

    PubMed Central

    Vaz, Kenneth M.; Brown, Justin M.; Shah, Sameer B.

    2014-01-01

    Peripheral nerve injury impairs motor, sensory, and autonomic function, incurring substantial financial costs and diminished quality of life. For large nerve gaps, proximal lesions, or chronic nerve injury, the prognosis for recovery is particularly poor, even with autografts, the current gold standard for treating small to moderate nerve gaps. In vivo elongation of intact proximal stumps towards the injured distal stumps of severed peripheral nerves may offer a promising new strategy to treat nerve injury. This review describes several nerve lengthening strategies, including a novel internal fixator device that enables rapid and distal reconnection of proximal and distal nerve stumps. PMID:25317163

  14. Adipose derived stem cells and nerve regeneration

    PubMed Central

    Faroni, Alessandro; Smith, Richard JP; Reid, Adam J

    2014-01-01

    Injuries to peripheral nerves are common and cause life-changing problems for patients alongside high social and health care costs for society. Current clinical treatment of peripheral nerve injuries predominantly relies on sacrificing a section of nerve from elsewhere in the body to provide a graft at the injury site. Much work has been done to develop a bioengineered nerve graft, precluding sacrifice of a functional nerve. Stem cells are prime candidates as accelerators of regeneration in these nerve grafts. This review examines the potential of adipose-derived stem cells to improve nerve repair assisted by bioengineered nerve grafts. PMID:25221589

  15. Job Displacement Among Single Mothers:

    PubMed Central

    Brand, Jennie E.; Thomas, Juli Simon

    2015-01-01

    Given the recent era of economic upheaval, studying the effects of job displacement has seldom been so timely and consequential. Despite a large literature associating displacement with worker well-being, relatively few studies focus on the effects of parental displacement on child well-being, and fewer still focus on implications for children of single parent households. Moreover, notwithstanding a large literature on the relationship between single motherhood and children’s outcomes, research on intergenerational effects of involuntary employment separations among single mothers is limited. Using 30 years of nationally representative panel data and propensity score matching methods, we find significant negative effects of job displacement among single mothers on children’s educational attainment and social-psychological well-being in young adulthood. Effects are concentrated among older children and children whose mothers had a low likelihood of displacement, suggesting an important role for social stigma and relative deprivation in the effects of socioeconomic shocks on child well-being. PMID:25032267

  16. Noncontact subnanometer measurement of transient surface displacement during action potential propagation

    NASA Astrophysics Data System (ADS)

    Akkin, Taner; Dave, Digant P.; Rylander, H. Grady, III; Milner, Thomas E.

    2005-04-01

    We have demonstrated non-contact, sub-nanometer optical measurement of neural surface displacement associated with action potential propagation without applying exogenous chemicals or reflection coatings. Signals recorded from crayfish leg nerve using a phase-sensitive optical low coherence reflectometer show that transient neural surface displacement due to action potential propagation is approximately 1 nm in amplitude and 1 ms in duration. Measured optical signals are coincident with electrical action potential arrival to the optical measurement site. Recent experiments indicate signals with similar amplitude and duration are observed in response to repetitive fast stimulation (200 stimuli/s).

  17. Malignant peripheral nerve sheath tumors.

    PubMed

    Gupta, Gaurav; Maniker, Allen

    2007-01-01

    Malignant peripheral nerve sheath tumors (MPNSTs) are rare soft tissue sarcomas of ectomesenchymal origin. The World Health Organization coined the term MPNST to replace previous heterogeneous and often confusing terminology, such as "malignant schwannoma," "malignant neurilemmoma," "neurogenic sarcoma," and "neurofibrosarcoma." Malignant peripheral nerve sheath tumors arise from major or minor peripheral nerve branches or sheaths of peripheral nerve fibers, and are derived from Schwann cells or pluripotent cells of neural crest origin. The Schwann cell is thought to be the major contributor to the formation of benign as well as malignant neoplasms of the nerve sheath. While this fact remains essentially true, the identity of cell of origin of the MPNST remains elusive, and has not yet been conclusively identified. It has been suggested that these tumors may have multiple cell line origins. In this review, the authors discuss the epidemiology, diagnosis, management, and treatment of MPNSTs. PMID:17613203

  18. Sacral nerve infiltrative endometriosis presenting as perimenstrual right-sided sciatica and bladder atonia: case report and description of surgical technique.

    PubMed

    Lemos, Nucelio; Kamergorodsky, Gil; Ploger, Christine; Castro, Rodrigo; Schor, Eduardo; Girão, Manoel

    2012-01-01

    Endometriosis infiltrating the sacral nerve roots is a rarely reported manifestation of the disease. The objectives of this article are to report such a case and to describe the surgical technique for laparoscopic decompression of sacral nerve roots and treatment of endometriosis at this site. The patient as a 38-year-old woman who had undergone 2 previous laparoscopic procedures for electrocoagulation of peritoneal endometriosis and self-reported perimenstrual right-sided sciatica and urinary retention. Clinical examination revealed allodynia (pain from a stimulus that does not normally cause pain) on the S2 to S4 dermatomes and hypoesthesia on part of the S3 dermatome. Magnetic resonance imaging showed an endometriotic nodule infiltrating the anterior rectal wall. Laparoscopic exploration of the sacral nerve roots demonstrated vascular compression of the lumbosacral trunk and endometriosis entrapping the S2 to S4 sacral nerve roots, with an endometrioma inside S3. The endometriosis was removed from the sacral nerve roots and detached from the sacral bone, and a nodulectomy of the anterior rectal wall was performed. Normal urinary function was restored on postoperative day 2, and pain resolved after a period of post-decompression. Intrapelvic causes of entrapment of sacral nerve roots are rarely described in the current literature, either because of misdiagnosis or actual rareness of the condition. Recognition of the clinical markers for these lesions may lead to an increase in diagnosis and specific treatment. PMID:22546428

  19. Perceived displacement explains wolfpack effect

    PubMed Central

    Šimkovic, Matúš; Träuble, Birgit

    2014-01-01

    We investigate the influence of perceived displacement of moving agent-like stimuli on the performance in dynamic interactive tasks. In order to reliably measure perceived displacement we utilize multiple tasks with different task demands. The perceived center of an agent's body is displaced in the direction in which the agent is facing and this perceived displacement is larger than the theoretical position of the center of mass would predict. Furthermore, the displacement in the explicit judgment is dissociated from the displacement obtained by the implicit measures. By manipulating the location of the pivot point, we show that it is not necessary to postulate orientation as an additional cue utilized by perception, as has been suggested by earlier studies. These studies showed that the agent's orientation influences the detection of chasing motion and the detection-related performance in interactive tasks. This influence has been labeled wolfpack effect. In one of the demonstrations of the wolfpack effect participants control a green circle on a display with a computer mouse. It has been shown that participants avoid display areas with agents pointing toward the green circle. Participants do so in favor of areas where the agents point in the direction perpendicular to the circle. We show that this avoidance behavior arises because the agent's pivot point selected by the earlier studies is different from where people locate the center of agent's body. As a consequence, the nominal rotation confounds rotation and translation. We show that the avoidance behavior disappears once the pivot point is set to the center of agent's body. PMID:25566114

  20. Renal carcinoma relapse presenting as a peripheral nerve sheath tumor: A case report and brief review of the literature.

    PubMed

    Cabrilo, I; Burkhardt, K; Schaller, K; Tessitore, E

    2013-06-01

    We report a rare case of renal carcinoma metastasis involving a lumbar nerve root. Metastases to nerve roots are rare occurrences, and to our knowledge, only six cases have been reported so far in the literature. The patient in this report presented with weakness in the right lower limb and intractable pain irradiating along the L5 dermatome. MRI findings revealed a right-sided L5 nerve root mass, suggestive of a schwannoma, involving the spinal ganglion and its extraforaminal region. Complete macroscopic resection of this mass was performed, and histopathologic analysis confirmed the lesion to be a metastasis of a renal clear cell carcinoma. Local radiotherapy was given and tyrosine kinase inhibitors administered. At 5 months, the patient was pain-free and his right limb weakness had completely resolved. A tumoral recurrence could be observed on the control MRI 5 months after surgery. This report presents the first case of a patient with a renal clear cell carcinoma metastasis to a L5 nerve root, as well as a brief review of previous cases of metastases to peripheral nerve roots. PMID:23806763

  1. Particle displacement tracking for PIV

    NASA Technical Reports Server (NTRS)

    Wernet, Mark P.

    1990-01-01

    A new Particle Imaging Velocimetry (PIV) data acquisition and analysis system, which is an order of magnitude faster than any previously proposed system has been constructed and tested. The new Particle Displacement Tracing (PDT) system is an all electronic technique employing a video camera and a large memory buffer frame-grabber board. Using a simple encoding scheme, a time sequence of single exposure images are time coded into a single image and then processed to track particle displacements and determine velocity vectors. Application of the PDT technique to a counter-rotating vortex flow produced over 1100 velocity vectors in 110 seconds when processed on an 80386 PC.

  2. Occipital nerve stimulation.

    PubMed

    Mammis, Antonios; Agarwal, Nitin; Mogilner, Alon Y

    2015-01-01

    Occipital nerve stimulation (ONS) is a form of neuromodulation therapy aimed at treating intractable headache and craniofacial pain. The therapy utilizes neurostimulating electrodes placed subcutaneously in the occipital region and connected to a permanently implanted programmable pulse generator identical to those used for dorsal column/spinal cord stimulation. The presumed mechanisms of action involve modulation of the trigeminocervical complex, as well as closure of the physiologic pain gate. ONS is a reversible, nondestructive therapy, which can be tailored to a patient's individual needs. Typically, candidates for successful ONS include those patients with migraines, Chiari malformation, or occipital neuralgia. However, recent MRSA infections, unrealistic expectations, and psychiatric comorbidities are generally contraindications. As with any invasive procedure, complications may occur including lead migration, infection, wound erosion, device failure, muscle spasms, and pain. The success of this therapy is dependent on careful patient selection, a preimplantation trial, meticulous implantation technique, programming strategies, and complication avoidance. PMID:25411143

  3. Roots and Shoots

    NSDL National Science Digital Library

    Lawrence Hall of Science

    2008-01-01

    In this outdoor activity, learners discover that plants aren't just shoots (stem, branches, leaves, and flowers) growing above ground, but contain plenty of roots growing underground—more than half the mass of a plant can be its roots. Learners dig up "mystery" plants to investigate their root structures, and match them to different types of root systems. Learners also learn about animals found near plant roots and how humans use roots.

  4. ?-Synuclein in cutaneous autonomic nerves

    PubMed Central

    Wang, Ningshan; Gibbons, Christopher H.; Lafo, Jacob

    2013-01-01

    Objective: To develop a cutaneous biomarker for Parkinson disease (PD). Methods: Twenty patients with PD and 14 age- and sex-matched control subjects underwent examinations, autonomic testing, and skin biopsies at the distal leg, distal thigh, and proximal thigh. ?-Synuclein deposition and the density of intraepidermal, sudomotor, and pilomotor nerve fibers were measured. ?-Synuclein deposition was normalized to nerve fiber density (the ?-synuclein ratio). Results were compared with examination scores and autonomic function testing. Results: Patients with PD had a distal sensory and autonomic neuropathy characterized by loss of intraepidermal and pilomotor fibers (p < 0.05 vs controls, all sites) and morphologic changes to sudomotor nerve fibers. Patients with PD had greater ?-synuclein deposition and higher ?-synuclein ratios compared with controls within pilomotor nerves and sudomotor nerves (p < 0.01, all sites) but not sensory nerves. Higher ?-synuclein ratios correlated with Hoehn and Yahr scores (r = 0.58–0.71, p < 0.01), with sympathetic adrenergic function (r = ?0.40 to ?0.66, p < 0.01), and with parasympathetic function (r = ?0.66 to ?0.77, p > 0.01). Conclusions: We conclude that ?-synuclein deposition is increased in cutaneous sympathetic adrenergic and sympathetic cholinergic fibers but not sensory fibers of patients with PD. Higher ?-synuclein deposition is associated with greater autonomic dysfunction and more advanced PD. These data suggest that measures of ?-synuclein deposition in cutaneous autonomic nerves may be a useful biomarker in patients with PD. PMID:24089386

  5. Job Displacement, Disability, and Divorce

    Microsoft Academic Search

    2004-01-01

    Earnings shocks should affect divorce probability by changing a couple's expected gains from marriage. We find that the divorce hazard rises after a spouse's job displacement but does not change after a spousal disability. This difference casts doubt on a purely pecuniary motivation for divorce following earnings shocks, since both types of shocks exhibit similar long-run economic consequences. Furthermore, the

  6. Displacement meters for liquid measurement

    SciTech Connect

    Kalivoda, R.J. [Smith Meter Inc., Erie, PA (United States)

    1995-12-01

    The purpose of this paper is to examine the positive displacement (PD) meter. The emphasis will be on the factors influencing the design and performance of the meter for liquid petroleum measurement. However, these factors can be applied to other liquids as well. Also included are discussions on PD meter enhancements that will increase the PD meter`s performance.

  7. Brainstem abnormalities and vestibular nerve enhancement in acute Neuroborreliosis

    PubMed Central

    2013-01-01

    Background Borreliosis is a widely distributed disease. Neuroborreliosis may present with unspecific symptoms and signs and often remains difficult to diagnose in patients with central nervous system symptoms, particularly if the pathognomonic erythema chronica migrans does not develop or is missed. Thus, vigilance is mandatory in cases with atypical presentation of the disease and with potentially severe consequences if not recognized early. We present a patient with neuroborreliosis demonstrating brain stem and vestibular nerve abnormalities on magnetic resonance imaging. Case presentation A 28-year-old Caucasian female presented with headaches, neck stiffness, weight loss, nausea, tremor, and gait disturbance. Magnetic resonance imaging showed T2-weighted hyperintense signal alterations in the pons and in the vestibular nerves as well as bilateral post-contrast enhancement of the vestibular nerves. Serologic testing of the cerebrospinal fluid revealed the diagnosis of neuroborreliosis. Conclusion Patients infected with neuroborreliosis may present with unspecific neurologic symptoms and magnetic resonance imaging as a noninvasive imaging tool showing signal abnormalities in the brain stem and nerve root enhancement may help in establishing the diagnosis. PMID:24359885

  8. Nerve entrapment syndromes in musicians.

    PubMed

    Wilson, Robert J; Watson, Jeffry T; Lee, Donald H

    2014-09-01

    Nerve entrapment syndromes are common in instrumental musicians. Carpal tunnel syndrome, ulnar neuropathy at the elbow, and thoracic outlet syndrome appear to be the most common. While electrodiagnostic studies may confirm the diagnosis of nerve entrapment, they may be falsely normal in musicians. Non-operative treatment with instrument and technique modification may help. Involvement with the musician's teacher to implement appropriate treatment is recommended. Outcomes for both non-operative and operative treatment for various nerve entrapment syndromes have yielded mostly good to excellent results, similar to the general population. PMID:24644143

  9. Character displacement in polyphenic tadpoles.

    PubMed

    Pfennig, D W; Murphy, P J

    2000-10-01

    Biologists have long known that closely related species are often phenotypically different where they occur together, but are indistinguishable where they occur alone. The causes of such character displacement are controversial, however. We used polyphenic spadefoot toad tadpoles (Spea bombifrons and S. multiplicata) to test the hypothesis that character displacement evolves to minimize competition for food. We also sought to evaluate the role of phenotypic plasticity in the mediation of competitive interactions between these species. Depending on their diet, individuals of both species develop into either a small-headed omnivore morph, which feeds mostly on detritus, or a large-headed carnivore morph, which specializes on shrimp. Laboratory experiments and surveys of natural ponds revealed that the two species were more dissimilar in their tendency to produce carnivores when they occurred together than when they occurred alone. This divergence in carnivore production was expressed as both character displacement (where S. multiplicata's propensity to produce carnivores was lower in sympatry than in allopatry) and as phenotypic plasticity (where S. multiplicata facultatively enhanced carnivore production in S. bombifrons, and S. bombifrons facultatively suppressed carnivore production in S. multiplicata). In separate experiments, we established that S. bombifrons (the species for which carnivore production was enhanced) was the superior competitor for shrimp. Conversely, S. multiplicata (the species for which carnivore production was suppressed and omnivore production enhanced) was the superior competitor for detritus. These results therefore demonstrate that selection to minimize competition for food can cause character displacement. They also suggest that both character displacement and phenotypic plasticity may mediate competitive interactions between species. PMID:11108600

  10. Nerve conduction studies in hand surgery

    Microsoft Academic Search

    David J Slutsky

    2003-01-01

    The treatment of nerve disorders of the upper extremity has become a highly specialized area. There has been an evolution in the electrodiagnostic approach for evaluating patients with these disorders. Portable automated nerve conduction testing systems are becoming popular for limited nerve conduction testing in the office. Differential latency testing can aid in the diagnosis of dynamic nerve entrapment disorders

  11. Electrodiagnostic confirmation of long thoracic nerve palsy

    Microsoft Academic Search

    P E Kaplan

    1980-01-01

    Long thoracic nerve latencies were measured in 25 normal subjects. The nerve was stimulated at Erb's point. Monopolar electrodes were used to record the motor evoked response from the serratus anterior muscle. The mean long thoracic nerve latency was 3.9 +\\/- 0.6 ms. Four athletes with unilateral, isolated long thoracic nerve palsies were compared with the control group and with

  12. Improved C3-4 transfer for treatment of root avulsion of the brachial plexus upper trunk

    PubMed Central

    Zou, Lin; Cao, Xuecheng; Li, Jing; Liu, Lifeng; Wang, Pingshan; Cai, Jinfang

    2012-01-01

    Experimental rats with root avulsion of the brachial plexus upper trunk were treated with the improved C3-4 transfer for neurotization of C5-6. Results showed that Terzis grooming test scores were significantly increased at 6 months after treatment, the latency of C5-6 motor evoked potential was gradually shortened, and the amplitude was gradually increased. The rate of C3 instead of C5 and the C4 + phrenic nerve instead of C6 myelinated nerve fibers crossing through the anastomotic stoma was approximately 80%. Myelinated nerve fibers were arranged loosely but the thickness of the myelin sheath was similar to that of the healthy side. In clinical applications, 39 patients with root avulsion of the brachial plexus upper trunk were followed for 6 months to 4.5 years after treatment using the improved C3 instead of C5 nerve root transfer and C4 nerve root and phrenic nerve instead of C6 nerve root transfer. Results showed that the strength of the brachial biceps and deltoid muscles recovered to level III–IV, scapular muscle to level III–IV, latissimus dorsi and pectoralis major muscles to above level III, and the brachial triceps muscle to level 0–III. Results showed that the improved C3-4 transfer for root avulsion of the brachial plexus upper trunk in animal models is similar to clinical findings and that C3-4 and the phrenic nerve transfer for neurotization of C5-6 can innervate the avulsed brachial plexus upper trunk and promote the recovery of nerve function in the upper extremity. PMID:25657692

  13. Surgical management of painful peripheral nerves.

    PubMed

    Elliot, David

    2014-07-01

    This article deals with the classification, assessment, and management of painful nerves of the distal upper limb. The author's preferred surgical and rehabilitation techniques in managing these conditions are discussed in detail and include (1) relocation of end-neuromas to specific sites, (2) division and relocation of painful nerves in continuity (neuromas-in-continuity and scar-tethered nerves) involving small nerves to the same sites, and (3) fascial wrapping of painful nerves in continuity involving larger nerves such as the median and ulnar nerves. The results of these treatments are presented as justification for current use of these techniques. PMID:24996473

  14. Micturition and the male genitourinary response to sacral root stimulation.

    PubMed

    Schmidt, R A; Bruschini, H; Van Gool, J; Tanagho, E A

    1979-09-01

    The sacral roots, because of their anatomic and functional organization, are well suited to chronic stimulation. Data from our previous experiments on female dogs suggested that effective voiding responses to stimulation could be obtained by using the ventral root of S2, the sacral nerve in canines with the greatest detrusor representation. Elimination of dorsal root afferents from the stimulus field was essential to the minimization of spinal reflex activity. A selective somatic neurotomy was also necessary to attenuate maximally sphincter activity. In the male, the presence of the prostate gland, the greater urethral length, and the erectile response to stimulation might result in compression of the urethra, compromising micturition. Sacral root stimulation was thus studied using both spinalized and nonspinalized male dogs; the results are discussed with a view toward the applicability of sacral root stimulation to effect micturition in male paraplegics, who comprise the largest percentage of this group of patients. PMID:313925

  15. Thirty minutes of low intensity electrical stimulation promotes nerve regeneration after sciatic nerve crush injury in a rat model.

    PubMed

    Alrashdan, Mohammad S; Park, Jong-Chul; Sung, Mi-Ae; Yoo, Sang Bae; Jahng, Jeong Won; Lee, Tae Hyung; Kim, Sung-June; Lee, Jong-Ho

    2010-06-01

    We investigated whether electrical stimulation (ES) applied directly for 30 minutes after crushing injury to the sciatic nerves of rats could improve nerve regeneration. Two groups of animals were used in this study (n = 20 each): the ES group received 30 minutes of low intensity ES (20 Hz pulse rate, 2 uA amplitude) immediately after a standard crush injury, while the control group received no stimulation after injury. Both groups were followed up for three weeks. The sciatic function index (SFI) was calculated weekly. Mean conduction velocity (MCV) and peak voltage (PV) were calculated, and the sensory neurons in L4 and L5 dorsal root ganglia (DRG) were traced with Fluorogold in retrograde fashion and quantified at the end of the follow up period. Histomorphometric studies were also carried out in both groups. The ES group showed improved functional and sensory recovery compared to the control group three weeks after injury. SFI, MCV and the number of retrogradely labeled sensory neurons were significantly higher in the ES group. Additionally, axon counts, myelin thicknesses and G-ratio values were also higher in the ES group. Quantitative real-time reverse transcriptase-polymerase chain reaction (RT-PCR) showed an elevated expression of brain derived neurotrophic factor (BDNF) in DRG sensory neurons of the ES group five days post-injury. Here, we present the first evidence that the application of ES for 30 minutes immediately following crush injury is effective to promote nerve regeneration in a rat sciatic nerve model. PMID:20873447

  16. The Study of Diagnostic Efficacy of Nerve Conduction Study Parameters in Cervical Radiculopathy

    PubMed Central

    Pawar, Sachin; Kashikar, Aditi; Shende, Vinod; Waghmare, Satish

    2013-01-01

    Background: Cervical Radiculopathy (CR) is a neurologic condition characterised by dysfunction of a cervical spinal nerve, the roots of the nerve, or both. Diagnostic criteria for CR are not well defined, and no universally accepted criteria for its diagnosis have been established. Clinical examination, radiological imaging and electrophysiologic evaluation are the different modalities to diagnose CR. The incidence of Cervical Spondylosis and related conditions is increasing in the present scenario and the use of radiologic examination is time consuming and uneconomical for the common Indian setup. Thus, there is a definite need to establish a cost effective, reliable, and accurate means for establishing the diagnosis of cervical radiculopathy. Electrodiagnostic tests are the closest to fulfill these criteria. Aim: To evaluate diagnostic utility of various motor and sensory nerve conduction study parameters in cervical radiculopathy. Setting and Design: It was a cross-sectional study conducted on 100 subjects of age > 40 years. Material and Methods: The consecutive patients clinically diagnosed to have cervical radiculopathy, referred from department of Orthopaedics were prospectively recruited for the motor and sensory nerve conduction study using RMS EMG EP Mark-II. Parameters studied were Compound Muscle Action Potential (CMAP), Distal Motor Latency (DML) and Conduction Velocity (CV) for motor nerves and Sensory Nerve Action Potential (SNAP) and CV for sensory nerves. Statistical Analysis: Study observations and results were analysed to find the Specificity, Sensitivity, Positive Predictive Value and Negative Predictive Value using SPSS 16.0. Results: Among various motor nerve conduction parameters CMAP was found to be more sensitive with high positive predicative value. CV was found to have greater specificity and DML had least negative predictive value. Sensory nerve conduction parameters were found to have less sensitivity but higher specificity as compared to motor parameters. Conclusion: Nerve conduction studies are useful supportive diagnostic tool for suspected cervical radiculopathy as they are found to have reliable sensitivity and specificity. PMID:24551610

  17. Crustal Displacements Due to Continental Water Loading

    NASA Technical Reports Server (NTRS)

    vanDam, T.; Wahr, J.; Milly, P. C. D.; Shmakin, A. B.; Blewitt, G.; Lavallee, D.; Larson, K. M.

    2001-01-01

    The effects of long-wavelength (> 100 km), seasonal variability in continental water storage on vertical crustal motions are assessed. The modeled vertical displacements (delta-r(sub M)) have root-mean-square (RMS) values for 1994-1998 as large as 8 mm with ranges up to 30 mm, and are predominantly annual in character. Regional strains are on the order of 20 nanostrain for tilt and 5 nanostrain for horizontal deformation. We compare delta-r(sub M) with observed Global Positioning System (GPS) heights (delta-r(sub O)) (which include adjustments to remove estimated effects of atmospheric pressure and annual tidal and non-tidal ocean loading) for 147 globally distributed sites. When the delta-r(sub O) time series are adjusted by delta-r(sub M), their variances are reduced, on average, by an amount equal to the variance of the delta-r(sub M). Of the delta-r(sub O) time series exhibiting a strong annual signal, more than half are found to have an annual harmonic that is in phase and of comparable amplitude with the annual harmonic in the delta-r(sub M). The delta-r(sub M) time series exhibit long-period variations that could be mistaken for secular tectonic trends or post-glacial rebound when observed over a time span of a few years.

  18. Overview of Optic Nerve Disorders

    MedlinePLUS

    ... Resources for Help and Information The One-Page Merck Manual of Health Medical Terms Conversion Tables Manuals available ... Papilledema Optic Neuritis Ischemic Optic Neuropathy Toxic Amblyopia Merck Manual > Patients & Caregivers > Eye Disorders > Optic Nerve Disorders 4 ...

  19. [Tumors of the phrenic nerve].

    PubMed

    Le Pimpec-Barthes, F; Martinod, E; Riquet, M; Saint-Blancard, P; Jancovici, R

    1998-02-01

    A schwannoma of the phrenic nerve is a rare disorder which presents as a tumour of the anterior mediastinum. It is seen in adults and is usually latent. We report two cases in elderly subjects in whom the phrenic nerve tumour had achieved a significant size. One of these schwannomas had degenerated into sarcomatous change which is the first case reported to the present time. PMID:9551520

  20. Sports and peripheral nerve injury

    Microsoft Academic Search

    Yasusuke Hirasawa; Kisaburo Sakakida

    1983-01-01

    Peripheral nerve injury is one of the serious compli cations of athletic injuries; however, they have rarely been reported. According to the report by Takazawa et al.,6 there were only 28 cases of peripheral nerve injury among 9,550 cases of sports injuries which had been treated in the previous 5 years at the clinic of the Japanese Athletic Association.The authors

  1. Magnetic-motor-root stimulation: review.

    PubMed

    Matsumoto, Hideyuki; Hanajima, Ritsuko; Terao, Yasuo; Ugawa, Yoshikazu

    2013-06-01

    Magnetic stimulation can activate the human central and peripheral nervous systems non-invasively and virtually painlessly. Magnetic stimulation over the spinal enlargements can activate spinal nerves at the neuroforamina (magnetic-neuroforamina stimulation). This stimulation method provides us with information related to the latency of compound-muscle action potential (CMAP), which is usually interpreted as peripheral motor-conduction time (PMCT). However, this stimulation method has faced several problems in clinical applications. One is that supramaximal CMAPs were unobtainable. Another is that magnetic stimulation did not usually activate the spinal nerves in the spinal canal, i.e., the cauda equina, which prevented an evaluation of its conduction. For these reasons, magnetic-neuroforamina stimulation was rarely used to evaluate the conduction of peripheral nerves. It was mainly used to evaluate the conduction of the corticospinal tract using the parameter of central motor-conduction time (CMCT), which was calculated by subtracting PMCT from the latency of motor-evoked potentials (MEPs) elicited by transcranial magnetic stimulation (TMS) over the primary motor cortex. Recently, supramaximal stimulation has been achieved in magnetic-neuroforamina stimulation, and this has contributed to the measurement of both CMAP size and latency. The achievement of supramaximal stimulation is ascribed to the increase in magnetic-stimulator output and a novel coil, the magnetic augmented translumbosacral stimulation (MATS) coil. The most proximal part of the cauda equina can be reliably activated using the MATS coil (magnetic-conus stimulation), thus contributing to the measurement of cauda equina conduction time (CECT) and cortico-conus motor-conduction time (CCCT). These recent developments in magnetic-motor-root stimulation enable us to more precisely evaluate the conduction of the proximal part of peripheral nerves and that of the corticospinal tract for lower-limb muscles. In this review article, we summarise the basic mechanisms, recent topics, clinical applications, comparison to electrical stimulation, pitfalls, safety and additional issues in magnetic-motor-root stimulation. PMID:23485367

  2. Specific projection of displaced retinal ganglion cells upon the accessory optic system in the pigeon (Columbia livia).

    PubMed Central

    Karten, J H; Fite, K V; Brecha, N

    1977-01-01

    In the pigeon, the nucleus of the basal optic root, a component of the accessory optic system, projects directly upon the vestibulo-cerebellum. This nucleus receives a prominent projection composed of large-diameter retinal axons, known as the basal optic root. The cells of origin of this tract were identified using horseradish peroxidase (donor:hydrogen-peroxide oxidoreductase, EC 1.11.1.7) as a retrograde marker. Injections of horseradish peroxidase confined primarily to the basal optic root nucleus labeled displaced ganglion cells of the contralateral retina. Cell sizes were 18-30 micronm and the dendrites of these cells were confined to the first stratum of the inner plexiform layer. Approximately 3700 displaced ganglion cells were labeled after injections of horseradish peroxidase into basal optic root. In contrast, no displaced ganglion cells were labeled after injections of horseradish peroxidase into the optic tectum, which labeled only cells in the ganglion cell layer proper. These findings indicate that displaced ganglion cells constitute a unique population of retinal neurons that give rise to a bisynaptic pathway directed to the cerebellum via the nucleus of the basal optic root. These displaced ganglion cells may play a major role inoculomotor reflexes. Images PMID:266216

  3. Peripheral nerve injury induces persistent vascular dysfunction and endoneurial hypoxia, contributing to the genesis of neuropathic pain.

    PubMed

    Lim, Tony K Y; Shi, Xiang Q; Johnson, Julia M; Rone, Malena B; Antel, Jack P; David, Samuel; Zhang, Ji

    2015-02-25

    Nerve injury is associated with microvascular disturbance; however, the role of the vascular system has not been well characterized in the context of neuropathic pain. Furthermore, ischemia is thought to play a role in a number of neuropathic pain conditions, and yet the role of hypoxia has also not been characterized in neuropathic pain conditions. In this study, we observed the presence of persistent endoneurial hypoxia in a mouse model of traumatic peripheral nerve injury, causing painful mononeuropathy. We attribute the ongoing hypoxia to microvascular dysfunction, endoneurial fibrosis, and increased metabolic requirements within the injured nerve. Increased lactate levels were observed in injured nerves, as well as increased oxygen consumption and extracellular acidification rates, suggesting that anaerobic glycolysis is required to maintain cellular ATP levels. Hypoxia causes a reduction in levels of the Na(+)/K(+) ATPase ion transporter in both cultured primary dorsal root ganglion neurons and injured peripheral nerve. A reduction of Na(+)/K(+) ATPase ion transporter levels likely contributes to the hyperexcitability of injured nerves. Physiological antagonism of hypoxia with hyperbaric oxygen alleviated mechanical allodynia in nerve-injured animals. These results suggest that hypoxia and the Na(+)/K(+) ATPase ion transporter may be a novel mechanistic target for the treatment of neuropathic pain. In addition, the findings support the possibility of using hypoxia activated pro-drugs to localize treatments for neuropathic pain and nerve injury to injured nerves. PMID:25716835

  4. Nerve conduction during Wallerian degeneration in the baboon

    Microsoft Academic Search

    R. W. Gilliatt; R. J. Hjorth

    1972-01-01

    Conduction in the lateral popliteal nerve of the baboon was studied during the course of Wallerian degeneration. Six nerves were examined. In each case the muscle response to nerve stimulation and the ascending nerve action potential were recorded daily until the nerve became inexcitable. The muscle response to nerve stimulation disappeared after four to five days, but ascending nerve action

  5. Retrieving three-dimensional displacement fields of mining areas from a single InSAR pair

    NASA Astrophysics Data System (ADS)

    Li, Zhi Wei; Yang, Ze Fa; Zhu, Jian Jun; Hu, Jun; Wang, Yun Jia; Li, Pei Xian; Chen, Guo Liang

    2015-01-01

    This paper presents a novel method for retrieving three-dimensional (3-D) displacement fields of mining areas from a single interferometric synthetic aperture radar (InSAR) pair. This method fully exploits the mechanism of mining subsidence, specifically the proportional relationship between the horizontal displacement and horizontal gradient of vertical displacements caused by underground mining. This method overcomes the limitations of conventional InSAR techniques that can only measure one-dimensional (1-D) deformation of mining area along the radar line-of-sight direction. The proposed method is first validated with simulated 3-D displacement fields, which are obtained by the FLAC software. The root mean square errors of the 3-D displacements retrieved by the proposed method are 13.7, 27.6 and 3.6 mm for the West-East, North-South, and Up-Down components, respectively. We then apply the proposed method to estimate the 3-D displacements of the Qianyingzi and the Xuzhou coal mines in China, respectively, each along with two Advanced Land Observing Satellite (ALOS) Phased Array Type L-band Synthetic Aperture Radar images. Results show that the estimated 3-D displacement is highly consistent with that of the field surveying. This demonstrates that the proposed method is an effective approach for retrieving 3-D mining displacement fields and will play an important role in mining-related hazard prevention and environment assessment under limited InSAR acquisitions.

  6. Optic Nerve Monitoring

    PubMed Central

    Schumann, Paul; Kokemüller, Horst; Tavassol, Frank; Lindhorst, Daniel; Lemound, Juliana; Essig, Harald; Rücker, Martin; Gellrich, Nils-Claudius

    2013-01-01

    Orbital and anterior skull base surgery is generally performed close to the prechiasmatic visual pathway, and clear strategies for detecting and handling visual pathway damage are essential. To overcome the common problem of a missed clinical examination because of an uncooperative or unresponsive patient, flash visual evoked potentials and electroretinograms should be used. These electrophysiologic examination techniques can provide evidence of intact, pathologic, or absent conductivity of the visual pathway when clinical assessment is not feasible. Visual evoked potentials and electroretinograms are thus essential diagnostic procedures not only for primary diagnosis but also for intraoperative evaluation. A decision for or against treatment of a visual pathway injury has to be made as fast as possible due to the enormous importance of the time elapsed with such injuries; this can be achieved additionally using multislice spiral computed tomography. The first-line conservative treatment of choice for such injuries is megadose methylprednisolone therapy. Surgery is used to decompress the orbital compartment by exposure of the intracanalicular part of the optic nerve in the case of optic canal compression. Modern craniomaxillofacial surgery requires detailed consideration of the diagnosis and treatment of traumatic visual pathway damage with the ultimate goal of preserving visual acuity. PMID:24436741

  7. Survival and regeneration of cutaneous and muscular afferent neurons after peripheral nerve injury in adult rats.

    PubMed

    Welin, Dag; Novikova, Liudmila N; Wiberg, Mikael; Kellerth, Jan-Olof; Novikov, Lev N

    2008-03-01

    Peripheral nerve injury induces the retrograde degeneration of dorsal root ganglion (DRG) cells, which affects predominantly the small-diameter cutaneous afferent neurons. This study compares the time-course of retrograde cell death in cutaneous and muscular DRG cells after peripheral nerve transection as well as neuronal survival and axonal regeneration after primary repair or nerve grafting. For comparison, spinal motoneurons were also included in the study. Sural and medial gastrocnemius DRG neurons were retrogradely labeled with the fluorescent tracers Fast Blue (FB) or Fluoro-Gold (FG) from the homonymous transected nerves. Survival of labeled sural and gastrocnemius DRG cells was assessed at 3 days and 1-24 weeks after axotomy. To evaluate axonal regeneration, the sciatic nerve was transected proximally at 1 week after FB-labeling of the sural and medial gastrocnemius nerves and immediately reconstructed using primary repair or autologous nerve grafting. Twelve weeks later, the fluorescent tracer Fluoro-Ruby (FR) was applied 10 mm distal to the sciatic lesion in order to double-label sural and gastrocnemius neurons that had regenerated across the repair site. Counts of labeled gastrocnemius DRG neurons did not reveal any significant retrograde cell death after nerve transection. In contrast, sural axotomy induced a delayed loss of sural DRG cells, which amounted to 22% at 4 weeks and 43-48% at 8-24 weeks postoperatively. Proximal transection of the sciatic nerve at 1 week after injury to the sural or gastrocnemius nerves neither further increased retrograde DRG degeneration, nor did it affect survival of sural or gastrocnemius motoneurons. Primary repair or peripheral nerve grafting supported regeneration of 53-60% of the spinal motoneurons and 47-49% of the muscular DRG neurons at 13 weeks postoperatively. In the cutaneous DRG neurons, primary repair or peripheral nerve grafting increased survival by 19-30% and promoted regeneration of 46-66% of the cells. The present results suggest that cutaneous DRG neurons are more sensitive to peripheral nerve injury than muscular DRG cells, but that their regenerative capacity does not differ from that of the latter cells. However, the retrograde loss of cutaneous DRG cells taking place despite immediate nerve repair would still limit the recovery of cutaneous sensory functions. PMID:18057922

  8. Alveolar nerve unfolding technique for synoptic analysis: visualization and quantification of inferior alveolar nerve tracings in three-dimensional cone-beam computed tomography.

    PubMed

    Jacquet, Wolfgang; Nyssen, Edgard; Sun, Yi; De Munter, Stephanie; Sijbers, Jan; Politis, Constantinus

    2013-07-01

    The aim of the technique presented here is to visualize the anatomical context of the inferior alveolar nerve (IAN) canal. For 2 cases, cone-beam computed tomography images of the mandible were obtained from patient files together with the manual preoperative IAN canal tracings. For both cases, similar to simulated panoramic images, a two-dimensional image is extracted from a three-dimensional cone-beam computed tomography image. Unlike panoramic images, the unfolding does not follow the general curvature of the mandible but follows the nerve tracing closely and places the traced nerve track on a horizontal central line. Because of the centering of the nerve tracing together with the nerve canal and its surroundings in a two-dimensional representation, the technique (ANUTSA [Alveolar Nerve Unfolding Technique for Synoptic Analysis]) allowed the first case to evidence the adjacency of root tips along the IAN, whereas in the second case the degree of penetration of the IAN by an implant is revealed. The global aspect of the representation through unfolding allowed for the detection of the anomalies and the IAN-penetrating lesion along the IAN canal at a glance. PMID:23851874

  9. Nerve conduits and growth factor delivery in peripheral nerve repair.

    PubMed

    Pfister, Lukas A; Papaloïzos, Michaël; Merkle, Hans P; Gander, Bruno

    2007-06-01

    Peripheral nerves possess the capacity of self-regeneration after traumatic injury. Transected peripheral nerves can be bridged by direct surgical coaptation of the two nerve stumps or by interposing autografts or biological (veins) or synthetic nerve conduits (NC). NC are tubular structures that guide the regenerating axons to the distal nerve stump. Early synthetic NC have primarily been made of silicone because of the relative flexibility and biocompatibility of this material and because medical-grade silicone tubes were readily available in various dimensions. Nowadays, NC are preferably made of biodegradable materials such as collagen, aliphatic polyesters, or polyurethanes. Although NC assist in guiding regenerating nerves, satisfactory functional restoration of severed nerves may further require exogenous growth factors. Therefore, authors have proposed NC with integrated delivery systems for growth factors or growth factor-producing cells. This article reviews the most important designs of NC with integrated delivery systems for localized release of growth factors. The various systems discussed comprise NC with growth factors being released from various types of matrices, from transplanted cells (Schwann cells or mesenchymal stem cells), or through genetic modification of cells naturally present at the site of injured tissue. Acellular delivery systems for growth factors include the NC wall itself, biodegradable microspheres seeded onto the internal surface of the NC wall, or matrices that are filled into the lumen of the NC and immobilize the growth factors through physical-chemical interactions or specific ligand-receptor interactions. A very promising and elegant system appears to be longitudinally aligned fibers inserted in the lumen of a NC that deliver the growth factors and provide additional guidance for Schwann cells and axons. This review also attempts to appreciate the most promising approaches and emphasize the importance of growth factor delivery kinetics. PMID:17565531

  10. Polyphenylquinoxalines via aromatic nucleophilic displacement

    NASA Technical Reports Server (NTRS)

    Hergenrother, Paul M. (Inventor); Connell, John W. (Inventor)

    1990-01-01

    Polyphenylquinoxalines are prepared by the nucleophilic displacement reaction of di(hydroxyphenyl)quinoxaline monomers with activated aromatic dihalides or dinitro compounds. The reactions are carried out in polar aprotic solvents using alkali metal bases at elevated temperatures under nitrogen. The di(hydroxyphenyl)quinoxaline monomers are prepared either by reacting stoichiometric quantities of aromatic bis(o-diamines) with a hydroxybenzil or by reacting o-phenylenediamine with a dihydroxybenzil or bis(hydroxyphenylglyoxylyl)benzene.

  11. Measuring tidal displacement using GPS

    NASA Astrophysics Data System (ADS)

    Balcerak, Ernie

    2013-06-01

    GPS is making possible high-precision, high-resolution measurements of tidal displacement that could not be achieved with other methods. Earth's surface deforms due to both body tides—the deformation of the solid Earth due to the pull of the Sun and the Moon—and ocean tides—the redistribution of water mass loading over Earth's surface. Body tides and ocean tides both have components that vary on semidiurnal, diurnal, and longer periods.

  12. The behavior of neuronal cells on tendon-derived collagen sheets as potential substrates for nerve regeneration.

    PubMed

    Alberti, Kyle A; Hopkins, Amy M; Tang-Schomer, Min D; Kaplan, David L; Xu, Qiaobing

    2014-04-01

    Peripheral nervous system injuries result in a decreased quality of life, and generally require surgical intervention for repair. Currently, the gold standard of nerve autografting, based on the use of host tissue such as sensory nerves is suboptimal as it results in donor-site loss of function and requires a secondary surgery. Nerve guidance conduits fabricated from natural polymers such as collagen are a common alternative to bridge nerve defects. In the present work, tendon sections derived through a process named bioskiving were studied for their potential for use as a substrate to fabricate nerve guidance conduits. We show that cells such as rat Schwann cells adhere, proliferate, and align along the fibrous tendon substrate which has been shown to result in a more mature phenotype. Additionally we demonstrate that chick dorsal root ganglia explants cultured on the tendon grow to similar lengths compared to dorsal root ganglia cultured on collagen gels, but also grow in a more oriented manner on the tendon sections. These results show that tendon sections produced through bioskiving can support directional nerve growth and may be of use as a substrate for the fabrication of nerve guidance conduits. PMID:24461939

  13. Ulnar nerve at the elbow – normative nerve conduction study

    PubMed Central

    2013-01-01

    Introduction A goal of our work was to perform nerve conduction studies (NCSs) of the ulnar nerve focused on the nerve conduction across the elbow on a sufficiently large cohort of healthy subjects in order to generate reliable reference data. Methods We examined the ulnar nerve in a position with the elbow flexion of 90o from horizontal. Motor response was recorded from the abductor digiti minimi muscle (ADM) and the first dorsal interosseous muscle (FDI). Results In our sample of 227 healthy volunteers we have examined 380 upper arms with the following results: amplitude (Amp)-CMAP(wrist) for ADM 9.6 ± 2.3 mV, MNCV at the forearm 60.4 ± 5.2 m/s, MNCV across the elbow 57.1 ± 5.9 m/s. Discussion Our study showed that motor NCSs of the ulnar nerve above elbow (AE) and below elbow (BE) in a sufficiently large cohort using methodology recommended by AANEM gave results well comparable for registration from FDI and ADM. PMID:23398737

  14. Fixture for Linearly Variable Displacement Transducers

    NASA Technical Reports Server (NTRS)

    Farley, G. L.; Baker, D. J.

    1985-01-01

    Original point of interest on shear panel tracked throughout loading. Technique and fixture measure out-of-plane displacements on shear panel using linearly variable displacement transducers (LVDT's) while tracking original panel location. Technique adaptable to any size shear panel.

  15. 20 CFR 211.8 - Displacement allowance.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...Benefits 1 2010-04-01 2010-04-01 false Displacement allowance. 211.8 Section 211.8 Employees' Benefits...RETIREMENT ACT CREDITABLE RAILROAD COMPENSATION § 211.8 Displacement allowance. An allowance paid to an employee...

  16. 20 CFR 211.8 - Displacement allowance.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...Benefits 1 2011-04-01 2011-04-01 false Displacement allowance. 211.8 Section 211.8 Employees' Benefits...RETIREMENT ACT CREDITABLE RAILROAD COMPENSATION § 211.8 Displacement allowance. An allowance paid to an employee...

  17. Recession Swells Count of Displaced Workers.

    ERIC Educational Resources Information Center

    Gardner, Jennifer M.

    1993-01-01

    The weak economy of the early 1990s increased the number of displaced workers. Although a disproportionately large share were in the goods-producing industries, displacements were much more widespread across industries than a decade earlier. (Author)

  18. Chitosan conduits combined with nerve growth factor microspheres repair facial nerve defects

    PubMed Central

    Liu, Huawei; Wen, Weisheng; Hu, Min; Bi, Wenting; Chen, Lijie; Liu, Sanxia; Chen, Peng; Tan, Xinying

    2013-01-01

    Microspheres containing nerve growth factor for sustained release were prepared by a compound method, and implanted into chitosan conduits to repair 10-mm defects on the right buccal branches of the facial nerve in rabbits. In addition, chitosan conduits combined with nerve growth factor or normal saline, as well as autologous nerve, were used as controls. At 90 days post-surgery, the muscular atrophy on the right upper lip was more evident in the nerve growth factor and normal sa-line groups than in the nerve growth factor-microspheres and autologous nerve groups. physiological analysis revealed that the nerve conduction velocity and amplitude were significantly higher in the nerve growth factor-microspheres and autologous nerve groups than in the nerve growth factor and normal saline groups. Moreover, histological observation illustrated that the di-ameter, number, alignment and myelin sheath thickness of myelinated nerves derived from rabbits were higher in the nerve growth factor-microspheres and autologous nerve groups than in the nerve growth factor and normal saline groups. These findings indicate that chitosan nerve conduits bined with microspheres for sustained release of nerve growth factor can significantly improve facial nerve defect repair in rabbits. PMID:25206635

  19. Resection of an oculomotor nerve cavernous angioma

    PubMed Central

    Obaid, Sami; Li, Shu; Denis, Daniel; Weil, Alexander G.; Bojanowski, Michel W.

    2014-01-01

    Background: Cavernous angiomas (CAs) of cranial nerves are rare, and their occurrence on the third cranial nerve is particularly rare. Surgical management of such CAs involving the third nerve is controversial. We describe a case of a symptomatic CA of the oculomotor nerve and review the literature in order to ascertain the relevance of surgical intervention. Case Description: A 71-year-old male patient presented with a 2-month history of progressive oculomotor nerve paralysis. CA of the oculomotor nerve was suspected on magnetic resonance imaging (MRI). The patient underwent complete resection of the CA through a subtemporal approach, preserving the integrity of the nerve. Histopathological analysis confirmed the diagnosis of CA. Despite optimal resection, the patient did not improve postoperatively. Conclusion: CAs of cranial nerves can cause rapid or progressive neurological deterioration. Whereas delayed treatment often leads to irreversible deficits, early nerve-sparing surgical excision of the CAs may potentially restore function. PMID:25184101

  20. Motor impairment following blockade of the infraorbital nerve: implications for the use of anesthetization techniques in speech research.

    PubMed

    Abbs, J H; Folkins, J W; Sivarajan, M

    1976-03-01

    Infraorbital nerve blocks were performed bilaterally in three subjects as a partial test of the hypothesis that some portion of the motor innervation to the facial muscles is provided in the trigeminal nerve. To ascertain the influence of this anesthetic procedure, the magnitude and rate of upper lip displacement (for speech and nonspeech tasks), the magnitude and rate of upper lip depression force, and diadochokinetic rate were transduced and recorded, both pre- and postanesthesia. All measures, along with bilateral muscle action potentials from orbicularis oris superior obtained for all force and displacement tasks, were reduced in magnitude as a function of the anesthetic condition. These findings, along with results from previous speech anesthetic studies, were interpreted to suggest that anesthesia of the infraorbital nerve produces measurable, if not substantial motor weakness in the supraoral musculature. The implications for previous studies, where anesthesia techniques have been employed, are discussed. PMID:1271798

  1. The movement of a nerve in a magnetic field: application to MRI Lorentz effect imaging.

    PubMed

    Roth, Bradley J; Luterek, Adam; Puwal, Steffan

    2014-05-01

    Direct detection of neural activity with MRI would be a breakthrough innovation in brain imaging. A Lorentz force method has been proposed to image nerve activity using MRI; a force between the action currents and the static MRI magnetic field causes the nerve to move. In the presence of a magnetic field gradient, this will cause the spins to precess at a different frequency, affecting the MRI signal. Previous mathematical modeling suggests that this effect is too small to explain the experimental data, but that model was limited because the action currents were assumed to be independent of position along the nerve and because the magnetic field was assumed to be perpendicular to the nerve. In this paper, we calculate the nerve displacement analytically without these two assumptions. Using realistic parameter values, the nerve motion is <5 nm, which induced a phase shift in the MRI signal of <0.02°. Therefore, our results suggest that Lorentz force imaging is beyond the capabilities of current technology. PMID:24728667

  2. 20 CFR 627.230 - Displacement.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Displacement. 627.230 Section 627.230...Program Requirements § 627.230 Displacement. (a) No currently employed worker...any participant (including partial displacement such as a reduction in the hours...

  3. The case for character displacement in plants.

    PubMed

    Beans, Carolyn M

    2014-03-01

    The evidence for character displacement as a widespread response to competition is now building. This progress is largely the result of the establishment of rigorous criteria for demonstrating character displacement in the animal literature. There are, however, relatively few well-supported examples of character displacement in plants. This review explores the potential for character displacement in plants by addressing the following questions: (1) Why aren't examples of character displacement in plants more common? (2) What are the requirements for character displacement to occur and how do plant populations meet those requirements? (3) What are the criteria for testing the pattern and process of character displacement and what methods can and have been used to address these criteria in the plant literature? (4) What are some additional approaches for studying character displacement in plants? While more research is needed, the few plant systems in which character displacement hypotheses have been rigorously tested suggest that character displacement may play a role in shaping plant communities. Plants are especially amenable to character displacement studies because of the experimental ease with which they can be used in common gardens, selection analyses, and breeding designs. A deeper investigation of character displacement in plants is critical for a more complete understanding of the ecological and evolutionary processes that permit the coexistence of plant species. PMID:24683467

  4. Water Mist Suppression in Conjunction with Displacement

    E-print Network

    Hickman, Mark

    Water Mist Suppression in Conjunction with Displacement Ventilation By Benjamin Piers Hume-2758 #12;#12;Displacement Water Mist System Masters of Fire Engineering Thesis 2003 i A man of genius makes Water Mist System Masters of Fire Engineering Thesis 2003 ii #12;Displacement Water Mist System Masters

  5. The case for character displacement in plants

    PubMed Central

    Beans, Carolyn M

    2014-01-01

    The evidence for character displacement as a widespread response to competition is now building. This progress is largely the result of the establishment of rigorous criteria for demonstrating character displacement in the animal literature. There are, however, relatively few well-supported examples of character displacement in plants. This review explores the potential for character displacement in plants by addressing the following questions: (1) Why aren't examples of character displacement in plants more common? (2) What are the requirements for character displacement to occur and how do plant populations meet those requirements? (3) What are the criteria for testing the pattern and process of character displacement and what methods can and have been used to address these criteria in the plant literature? (4) What are some additional approaches for studying character displacement in plants? While more research is needed, the few plant systems in which character displacement hypotheses have been rigorously tested suggest that character displacement may play a role in shaping plant communities. Plants are especially amenable to character displacement studies because of the experimental ease with which they can be used in common gardens, selection analyses, and breeding designs. A deeper investigation of character displacement in plants is critical for a more complete understanding of the ecological and evolutionary processes that permit the coexistence of plant species. PMID:24683467

  6. Progranulin contributes to endogenous mechanisms of pain defense after nerve injury in mice

    PubMed Central

    Lim, Hee-Young; Albuquerque, Boris; Häussler, Annett; Myrczek, Thekla; Ding, Aihao; Tegeder, Irmgard

    2012-01-01

    Abstract Progranulin haploinsufficiency is associated with frontotemporal dementia in humans. Deficiency of progranulin led to exaggerated inflammation and premature aging in mice. The role of progranulin in adaptations to nerve injury and neuropathic pain are still unknown. Here we found that progranulin is up-regulated after injury of the sciatic nerve in the mouse ipsilateral dorsal root ganglia and spinal cord, most prominently in the microglia surrounding injured motor neurons. Progranulin knockdown by continuous intrathecal spinal delivery of small interfering RNA after sciatic nerve injury intensified neuropathic pain-like behaviour and delayed the recovery of motor functions. Compared to wild-type mice, progranulin-deficient mice developed more intense nociceptive hypersensitivity after nerve injury. The differences escalated with aging. Knockdown of progranulin reduced the survival of dissociated primary neurons and neurite outgrowth, whereas addition of recombinant progranulin rescued primary dorsal root ganglia neurons from cell death induced by nerve growth factor withdrawal. Thus, up-regulation of progranulin after neuronal injury may reduce neuropathic pain and help motor function recovery, at least in part, by promoting survival of injured neurons and supporting regrowth. A deficiency in this mechanism may increase the risk for injury-associated chronic pain. PMID:21645236

  7. Topography and time course of changes in spinal neuropeptide Y immunoreactivity after spared nerve injury

    PubMed Central

    Intondi, A.B.; Zadina, J.E.; Zhang, X.; Taylor, B.K.

    2009-01-01

    We used a new computer-assisted method to precisely localize and efficiently quantify increases in NPY immunoreactivity (NPY-ir) along the mediolateral axis of the L4 dorsal horn following transection of either the tibial and common peroneal nerves (thus sparing the sural branch, spared nerve injury, SNI), the tibial nerve, or the common peroneal and sural nerves. Two weeks after SNI, NPY-ir increased within the tibial and peroneal innervation territories; however, NPY-ir in the central-lateral region (innervated by the spared sural nerve) was indistinguishable from that of SHAM. Conversely, transection of the sural and common peroneal nerved induced an increase in NPY-ir in the central-lateral region, while leaving the medial region (innervated by the tibial nerve) unaffected. All nerve injuries increased NPY-ir in dorsal root ganglia (DRG) and nucleus gracilis (NG). By 24 wk, both NPY-ir up-regulation in the dorsal horn and hyper-responsivity to cold and noxious mechanical stimuli had resolved. Conversely, NPY-ir in DRG and NG, and hypersensitivity to non-noxious static mechanical stimuli, did not resolve within 24 wk. Over this time course, the average cross-sectional area of NPY-immunoreactive DRG neurons increased by 150 ?m2. We conclude that the up-regulation of NPY after SNI is restricted to medial zones of the dorsal horn, and therefore cannot act directly upon synapses within the more lateral (sural) zones to control sural nerve hypersensitivity. Instead, we suggest that NPY in the medial dorsal horn tonically inhibits hypersensitivity by interrupting mechanisms of central sensitization and integration of sensory signals at the spinal and supraspinal levels. PMID:19879928

  8. Ultrasound of tendons and nerves.

    PubMed

    Martinoli, Carlo; Bianchi, Stefano; Dahmane, M'Hamed; Pugliese, Francesca; Bianchi-Zamorani, Maria Pia; Valle, Maura

    2002-01-01

    Tendons and nerves represent probably one of the best application of musculoskeletal US due to the high lesion detection rate and accuracy of US combined with its low cost, wide availability, and ease of use. The refinement of high-frequency broadband linear-array transducers, and sensitive color and power Doppler technology, have improved the ability of US to detect fine textural abnormalities of these structures as well as to identify a variety of pathological conditions. Characteristic echotextural patterns, closely resembling the histological ones, are typically depicted in these structures using high US frequencies. In tendon imaging, US can assess dislocations, degenerative changes and tendon tears, including intrasubstance tears, longitudinal splits, partial and complete rupture, inflammatory conditions and tendon tumors, as well as postoperative findings. In nerve imaging, US can support clinical and electrophysiological testing for detection of compressing lesions caused by nerve entrapment in a variety of osteofibrous tunnels of the limbs and extremities. Congenital anomalies, nerve tears, and neurogenic tumors can also be diagnosed. Overall, US is an effective technique for imaging tendons and nerves. In most cases, a focused US examination can be performed more rapidly and efficiently than MR imaging. PMID:11868073

  9. Pericycle cell proliferation and lateral root initiation in Arabidopsis.

    PubMed

    Dubrovsky, J G; Doerner, P W; Colón-Carmona, A; Rost, T L

    2000-12-01

    In contrast with other cells generated by the root apical meristem in Arabidopsis, pericycle cells adjacent to the protoxylem poles of the vascular cylinder continue to cycle without interruption during passage through the elongation and differentiation zones. However, only some of the dividing pericycle cells are committed to the asymmetric, formative divisions that give rise to lateral root primordia (LRPs). This was demonstrated by direct observation and mapping of mitotic figures, cell-length measurements, and the histochemical analysis of a cyclin-GUS fusion protein in pericycle cells. The estimated duration of a pericycle cell cycle in the root apical meristem was similar to the interval between cell displacement from the meristem and the initiation of LRP formation. Developmentally controlled LRP initiation occurs early, 3 to 8 mm from the root tip. Thus the first growth control point in lateral root formation is defined by the initiation of primordia in stochastic patterns by cells passing through the elongation and young differentiation zones, up to where lateral roots begin to emerge from the primary root. Therefore, the first growth control point is not restricted to a narrow developmental window. We propose that late LRP initiation is developmentally unrelated to the root apical meristem and is operated by a second growth control point that can be activated by environmental cues. The observation that pericycle cells divide and lateral root primordia form without intervening mitotic quiescence suggests that lateral organ formation in roots and shoots might not be as fundamentally different as previously thought. PMID:11115882

  10. Pericycle Cell Proliferation and Lateral Root Initiation in Arabidopsis1

    PubMed Central

    Dubrovsky, Joseph G.; Doerner, Peter W.; Colón-Carmona, Adán; Rost, Thomas L.

    2000-01-01

    In contrast with other cells generated by the root apical meristem in Arabidopsis, pericycle cells adjacent to the protoxylem poles of the vascular cylinder continue to cycle without interruption during passage through the elongation and differentiation zones. However, only some of the dividing pericycle cells are committed to the asymmetric, formative divisions that give rise to lateral root primordia (LRPs). This was demonstrated by direct observation and mapping of mitotic figures, cell-length measurements, and the histochemical analysis of a cyclin-GUS fusion protein in pericycle cells. The estimated duration of a pericycle cell cycle in the root apical meristem was similar to the interval between cell displacement from the meristem and the initiation of LRP formation. Developmentally controlled LRP initiation occurs early, 3 to 8 mm from the root tip. Thus the first growth control point in lateral root formation is defined by the initiation of primordia in stochastic patterns by cells passing through the elongation and young differentiation zones, up to where lateral roots begin to emerge from the primary root. Therefore, the first growth control point is not restricted to a narrow developmental window. We propose that late LRP initiation is developmentally unrelated to the root apical meristem and is operated by a second growth control point that can be activated by environmental cues. The observation that pericycle cells divide and lateral root primordia form without intervening mitotic quiescence suggests that lateral organ formation in roots and shoots might not be as fundamentally different as previously thought. PMID:11115882

  11. Overcoming peripheral nerve gap defects using an intact nerve bridge in a rabbit model.

    PubMed

    McCallister, Wren V; McCallister, Erika L; Trumble, Stacey A; Trumble, Thomas E

    2005-04-01

    This study investigated the intact nerve bridge technique for overcoming peripheral nerve gap defects in a rabbit model. To create the intact nerve bridge, a 1-cm segment of the peroneal nerve is resected leaving a gap defect. The proximal and distal peroneal nerve stumps are sutured 1 cm apart, in an end-to-side fashion, to the intact tibial nerve epineurium. Four experimental groups were used (n = 10): primary repair of resected segment; intact nerve bridge; nerve autograft; and gap in situ control. Evaluation after 12 weeks included measurement of isometric muscle contraction force, axonal counting, wet muscle weights, and histologic examination. The results of this study support two main conclusions, in a rabbit model: (a) regenerating axons can use the epineurium of an intact nerve to bridge a gap defect; (b) there is no significant difference in the functional recovery between standard nerve autografts and the intact nerve bridge technique. PMID:15880300

  12. Facial-hypoglossal nerve anastomosis using laser nerve welding.

    PubMed

    Hwang, Kun; Kim, Sun Goo; Kim, Dae Joong

    2006-07-01

    The aim of this study is to compare laser nerve welding to microsurgical suturing of hypoglossal-facial nerve anastomosis (HFA), and a result of immediate to delayed repair, and to evaluate the effect of laser nerve welding on HFA for reanimation of facial palsy. The first group of five rats underwent immediate HFA by microsurgical suturing and the second group of five rats by CO2 laser welding. The third group of five rats underwent delayed HFA by microsurgical suturing, and the fourth group of five rats by laser nerve welding. The fifth group of five rats served as controls, with intact hypoglossal and facial nerve. In all rats of the four different treatment groups, cholera toxin B subunit (CTb) was injected in the epineurium distal to the anastomosis site on the postoperative 6th week and in the normal hypoglossal nerve in the five rats of the control group. Neurons labeled CTb of hypoglossal nuclei were positive immunohistochemically, and the numbers were counted. In the immediate HFA groups, CTb-positive neurons were 751 +/- 247 in the laser welding group (n = 5) and 888 +/- 60 in the microsurgical suturing group (n = 5). There was no significant difference (P = 0.117). In the delayed HFA groups, CTb-positive neurons were 749 +/- 54 in the laser welding group (n = 5) and 590 +/- 169 in the microsurgical suturing group (n = 5). The difference was not significant (P = 0.116). There was no significant difference between immediate and delayed anastomosis in the laser welding group (P = 0.600), but there was significance between immediate and delayed anastomosis in the microsurgical suturing group (P = 0.009). Injected CTb in intact hypoglossal neurons (n = 5) were labeled 1,003 +/- 52. No dehiscence in the laser welding site of nerve anastomosis was seen at the time of re-exploration for injection of CTb in all 10 rats. This study shows that the regeneration of anastomosed hypoglossal-facial nerve was affected similarly by laser welding and microsurgical suturing, and more effective, especially in delayed repair. PMID:16877915

  13. Interleukin-10 levels in rat models of nerve damage and neuropathic pain.

    PubMed

    Khan, Junad; Ramadan, Khaled; Korczeniewska, Olga; Anwer, Muhammad Moin; Benoliel, Rafael; Eliav, Eli

    2015-04-10

    Interleukin-10 (IL-10) is an anti-inflammatory cytokine that has been shown to play a role in inflammatory and autoimmune disorders as well as in neuropathic pain conditions. The objective of the present study was to assess the levels of IL-10 in rat's dorsal root ganglion (DRG) and the sciatic nerve following four different forms of sciatic nerve injury. The models used to induce the injury included two models of partial nerve injury: partial sciatic ligation (PSL) and chronic constriction injury (CCI), a model of complete sciatic transection (CST) and a model of perineural inflammation with minimal nerve damage (neuritis). Withdrawal responses for mechanical stimulus and withdrawal latency for thermal stimulation were used to measure mechanical and thermal hyperalgesia, respectively, and duration of the nociceptive withdrawal reflex to mechanical stimulus was used to measure mechanical hyperalgesia. The affected and contra-lateral nerves and the affected side DRG IL-10 levels were assessed by the means of enzyme-linked immunosorbent assay (ELISA), 3 and 8 days following the procedure and were compared to naïve rats' IL-10 levels. The rats exposed to CCI and neuritis developed significant mechanical and thermal hyperalgesia as well as mechanical hyperalgesia 3 and 8 days following the surgical procedure. Rats exposed to CST did not respond to mechanical stimulation and developed thermal hypoalgesia 3 and 8 days after the surgery. The DRG IL-10 levels were significantly reduced 3 and 8 days following CCI and PSL, significantly increased 3 and 8 days following CST, and remained unchanged following neuritis. The sciatic nerve IL-10 levels reduced significantly in both injured and contra-lateral nerves 3 and 8 days following CCI and PSL, elevated significantly in the injured but not in the contra-lateral nerve 3 and 8 days following CST and remained unchanged following neuritis. The results of this study suggest that IL-10's role in the neuropathic pain etiology may be specific to nerve injury type. Complete nerve transection increases while partial nerve injury reduces IL-10 levels in the involved nerve, and DRG. Perineural inflammation with minimal nerve damage has no effect on IL-10 levels. PMID:25757362

  14. Vulnerability of dorsal root neurons and fibers toward methylmercury toxicity: a morphological evaluation

    SciTech Connect

    Yip, R.K.; Chang, L.W.

    1981-10-01

    The selective and relative sensitivity of various components (dorsal root neurons, dorsal root fibers, and ventral root fibers) of the dorsal root ganglia toward methylmercury toxicity were investigated. Charles River rats were orally administered methymercury chloride at a daily dose of 2.0 mg/kg body wt for 8 weeks. Dorsal root ganglia (L/sub 1/-S/sub 1/) were examined with light and electron microscopy. Extensive Wallerian-like degeneration was observed in the dorsal root fibers while no significant changes were found in the dorsal root neurons and in the ventral root fibers at the light-microscopic level. At the electron-microscopic level, only minor and possibly reversible changes, such as increase in lysosomes, neurofilamentous proliferation, and disintegration of the Nissl substance, were observed in the neuronal cell bodies while severe and irreversible degenerative changes occurred in the dorsal root fibers. No remarkable pathological changes were observed in the ventral root fibers. Schwann cells became hypertrophied and transformed into actively phagocytosing macrophages. It is concluded that while the dorsal root ganglia are highly vulnerable to the toxicity of methylmercury, the relative sensitivity to the toxic impact is: dorsal root fiber > dorsal root neuron (nerve cell body) > ventral root fibers.

  15. Second-order Darboux displacements

    NASA Astrophysics Data System (ADS)

    Samsonov, B. F.; Glasser, M. L.; Negro, J.; Nieto, L. M.

    2003-10-01

    The potentials for a one-dimensional Schrödinger equation that are displaced along the x-axis under second-order Darboux transformations, called 2-SUSY invariant, are characterized in terms of a differential-difference equation. The solutions of the Schrödinger equation with such potentials are given analytically for any value of the energy. The method is illustrated by a two-soliton potential. It is proved that a particular case of the periodic Lamé-Ince potential is 2-SUSY invariant. Both Bloch solutions of the corresponding Schrödinger equation are found for any value of the energy. A simple analytic expression for a family of two-gap potentials is derived.

  16. Errors in diagnosis of polyneuropathy: three cases of chronic lumbosacral root impairment.

    PubMed

    Padua, L; Padua, R; Nazzaro, M; Tonali, P

    1998-01-01

    In the last years very precise diagnostic investigations have been introduced to allow accurate diagnosis of pathologies affecting the major part of peripheral nerves; nevertheless, some avoidable misdiagnosis still occurs. For instance, the neurophysiological pattern observed in chronic compression of nerve roots may mimic an axonal polyneuropathy, especially when compression occurs in post-ganglionic tract of dorsal root (in this case sensory nerve conduction studies show decreased or absent response). A clinical-neurophysiological dissociation may be noted in cases with pre-ganglionic impairment of dorsal root (clinical sensory deficit in presence of normal amplitude of sensory response). During the past two years we observed 3 cases with diagnosis of polyneuropathy that, after further studies, appeared affected by severe chronic compression of lumbo-sacral nerve roots. Our data suggest that in those cases with suspected polyneuropathy, in which the neurophysiological picture is characterized by the exclusive axonal (and myelinic) involvement of motor and/or sensory peripheral nerve of lower limbs, neuroimaging of radicular structures must be performed. These further investigations may avoid severe and irreversible damage to neural tissues. PMID:10959253

  17. Effect of pulsed infrared lasers on neural conduction and axoplasmic transport in sensory nerves

    NASA Astrophysics Data System (ADS)

    Wesselmann, Ursula; Rymer, William Z.; Lin, Shien-Fong

    1990-06-01

    Over the past ten years there has been an increasing interest in the use of lasers for neurosurgical and neurological procedures. Novel recent applications range from neurosurgical procedures such as dorsal root entry zone lesions made with argon and carbon dioxide microsurgical lasers to pain relief by low power laser irradiation of the appropriate painful nerve or affected region1 '2 However, despite the widespread clinical applications of laser light, very little is known about the photobiological interactions between laser light and nervous tissue. The present studies were designed to evaluate the effects of pulsed Nd:YAG laser light on neural impulse conduction and axoplasmic transport in sensory nerves in rats and cats. Our data indicate that Q-switched Nd:YAG laser irradiation can induce a preferential impairment of (1) the synaptic effects of small afferent fibers on dorsal horn cells in the spinal cord and of (2) small slow conducting sensory nerve fibers in dorsal roots and peripheral nerves. These results imply that laser light might have selective effects on impulse conduction in slow conducting sensory nerve fibers. In agreement with our elecirophysiological observations recent histological data from our laboratory show, that axonal transport of the enzyme horseradish peroxidase is selectively impaired in small sensory nerve fibers. In summary these data indicate, that Q-switched Nd:YAG laser irradiation can selectively impair neural conduction and axoplasmic transport in small sensory nerve fibers as compared to fast conducting fibers. A selective influence of laser irradiation on slow conducting fibers could have important clinical applications, especially for the treatment of chronic pain.

  18. Axial differences in the reinnervation of the goldfish optic tectum by regenerating optic nerve fibres

    Microsoft Academic Search

    R. M. Gaze; S. C. Sharma

    1970-01-01

    1.In adult goldfish the caudal half of the optic tectum was removed. In some animals the corresponding optic nerve was crushed as well. The animals were later used to map the retinotectal projection.2.In fishes with the tectal lesion only, the displaced projection from the missing half-tectum was found to be partially restored over the residual rostral half-tectum, in appropriate retinotopic

  19. Median Nerve Injury following K-wire Fixation of Bennett’s Fracture—Lessons Learned

    PubMed Central

    Shetty, Sanath K.; Hanna, Amir W.

    2010-01-01

    Bennett's fracture is a relatively common injury. The fracture is unstable due to the displacing forces acting on the distal fragment and very commonly treated by stabilization with Kirschner wires. This would seem a relatively safe procedure, and injury to the median nerve has never been reported. We present this unusual complication following one such procedure with the evaluation of a safe approach utilizing the relevant surgical and radiological anatomy. PMID:22131930

  20. Design, fabrication and evaluation of a conforming circumpolar peripheral nerve cuff electrode for acute experimental use

    PubMed Central

    Foldes, Emily L.; Ackermann, D. Michael; Bhadra, Niloy; Kilgore, Kevin L.; Bhadra, Narendra

    2011-01-01

    Nerve cuff electrodes are a principle tool of basic and applied electro-neurophysiology studies and are championed for their ability to achieve good nerve recruitment with low thresholds. We describe the design and method of fabrication for a novel circumpolar peripheral nerve electrode for acute experimental use. This cylindrical cuff-style electrode provides approximately 270 degrees of radial electrode contact with a nerve for each of an arbitrary number of contacts, has a profile that allows for simple placement and removal in an acute nerve preparation, and is designed for adjustment of the cylindrical diameter to ensure a close fit on the nerve. For each electrode, the electrical contacts were cut from 25 µm platinum foil as an array so as to maintain their positions relative to each other within the cuff. Lead wires were welded to each intended contact. The structure was then molded in silicone elastomer, after which the individual contacts were electrically isolated. The final electrode was curved into a cylindrical shape with an inner diameter corresponding to that of the intended target nerve. The positions of these contacts were well maintained during the molding and shaping process and failure rates during fabrication due to contact displacements were very low. Established electrochemical measurements were made on one electrode to confirm expected behavior for a platinum electrode and to measure the electrode impedance to applied voltages at different frequencies. These electrodes have been successfully used for nerve stimulation, recording, and conduction block in a number of different acute animal experiments by several investigators. PMID:21187115

  1. Interferometric fiber optic displacement sensor

    DOEpatents

    Farah, J.

    1999-04-06

    A method is presented to produce a change in the optical path length in the gap between two single mode optical fibers proportional to the lateral displacement of either fiber end normal to its axis. This is done with the use of refraction or diffraction at the interface between a guiding and non-guiding media to change the direction of propagation of the light in the gap. A method is also presented for laying a waveguide on a cantilever so that the displacement of the tip of the cantilever produces a proportional path length change in the gap by distancing the waveguide from the neutral axis of the cantilever. The fiber is supported as a cantilever or a waveguide is deposited on a micromachined cantilever and incorporated in an interferometer which is made totally on a silicon substrate with the use of integrated-optic technology. A resonant element in the form of a micro-bridge is incorporated in the ridge waveguide and produces a frequency output which is readily digitizeable and immune to laser frequency noise. Finally, monolithic mechanical means for phase modulation are provided on the same sensor substrate. This is done by vibrating the cantilever or micro-bridge either electrically or optically. 23 figs.

  2. Interferometric fiber optic displacement sensor

    DOEpatents

    Farah, John (M.I.T. Branch P.O. Box 301, Cambridge, MA 02139)

    1995-01-01

    A method is presented to produce a change in the optical path length in the gap between two single mode optical fibers proportional to the lateral displacement of either fiber end normal to its axis. This is done with the use of refraction or diffraction at the interface between a guiding and non-guiding media to change the direction of propagation of the light in the gap. A method is also presented for laying a waveguide on a cantilever so that the displacement of the tip of the cantilever produces a proportional path length change in the gap by distancing the waveguide from the neutral axis of the cantilever. The fiber is supported as a cantilever or a waveguide is deposited on a micromachined cantilever and incorporated in an interferometer which is made totally on a silicon substrate with the use of integrated-optic technology. A resonant element in the form of a micro-bridge is incorporated in the ridge waveguide and produces a frequency output which is readily digitizeable and immune to laser frequency noise. Finally, monolithic mechanical means for phase modulation are provided on the same sensor substrate. This is done by vibrating the cantilever or micro-bridge either electrically or optically.

  3. Interferometric fiber optic displacement sensor

    DOEpatents

    Farah, John (M.I.T. P.O. Box 397301, Cambridge, MA 02139)

    1999-01-01

    A method is presented to produce a change in the optical path length in the gap between two single mode optical fibers proportional to the lateral displacement of either fiber end normal to its axis. This is done with the use of refraction or diffraction at the interface between a guiding and non-guiding media to change the direction of propagation of the light in the gap. A method is also presented for laying a waveguide on a cantilever so that the displacement of the tip of the cantilever produces a proportional path length change in the gap by distancing the waveguide from the neutral axis of the cantilever. The fiber is supported as a cantilever or a waveguide is deposited on a micromachined cantilever and incorporated in an interferometer which is made totally on a silicon substrate with the use of integrated-optic technology. A resonant element in the form of a micro-bridge is incorporated in the ridge waveguide and produces a frequency output which is readily digitizeable and immune to laser frequency noise. Finally, monolithic mechanical means for phase modulation are provided on the same sensor substrate. This is done by vibrating the cantilever or micro-bridge either electrically or optically.

  4. Interferometric fiber optic displacement sensor

    DOEpatents

    Farah, J.

    1995-05-30

    A method is presented to produce a change in the optical path length in the gap between two single mode optical fibers proportional to the lateral displacement of either fiber end normal to its axis. This is done with the use of refraction or diffraction at the interface between a guiding and non-guiding media to change the direction of propagation of the light in the gap. A method is also presented for laying a waveguide on a cantilever so that the displacement of the tip of the cantilever produces a proportional path length change in the gap by distancing the waveguide from the neutral axis of the cantilever. The fiber is supported as a cantilever or a waveguide is deposited on a micromachined cantilever and incorporated in an interferometer which is made totally on a silicon substrate with the use of integrated-optic technology. A resonant element in the form of a micro-bridge is incorporated in the ridge waveguide and produces a frequency output which is readily digitizeable and immune to laser frequency noise. Finally, monolithic mechanical means for phase modulation are provided on the same sensor substrate. This is done by vibrating the cantilever or micro-bridge either electrically or optically. 29 figs.

  5. A Theoretical Model to Predict Both Horizontal Displacement and Vertical Displacement for Electromagnetic Induction-Based Deep Displacement Sensors

    PubMed Central

    Shentu, Nanying; Zhang, Hongjian; Li, Qing; Zhou, Hongliang; Tong, Renyuan; Li, Xiong

    2012-01-01

    Deep displacement observation is one basic means of landslide dynamic study and early warning monitoring and a key part of engineering geological investigation. In our previous work, we proposed a novel electromagnetic induction-based deep displacement sensor (I-type) to predict deep horizontal displacement and a theoretical model called equation-based equivalent loop approach (EELA) to describe its sensing characters. However in many landslide and related geological engineering cases, both horizontal displacement and vertical displacement vary apparently and dynamically so both may require monitoring. In this study, a II-type deep displacement sensor is designed by revising our I-type sensor to simultaneously monitor the deep horizontal displacement and vertical displacement variations at different depths within a sliding mass. Meanwhile, a new theoretical modeling called the numerical integration-based equivalent loop approach (NIELA) has been proposed to quantitatively depict II-type sensors’ mutual inductance properties with respect to predicted horizontal displacements and vertical displacements. After detailed examinations and comparative studies between measured mutual inductance voltage, NIELA-based mutual inductance and EELA-based mutual inductance, NIELA has verified to be an effective and quite accurate analytic model for characterization of II-type sensors. The NIELA model is widely applicable for II-type sensors’ monitoring on all kinds of landslides and other related geohazards with satisfactory estimation accuracy and calculation efficiency. PMID:22368467

  6. Nerve lesioning with direct current

    NASA Astrophysics Data System (ADS)

    Ravid, E. Natalie; Shi Gan, Liu; Todd, Kathryn; Prochazka, Arthur

    2011-02-01

    Spastic hypertonus (muscle over-activity due to exaggerated stretch reflexes) often develops in people with stroke, cerebral palsy, multiple sclerosis and spinal cord injury. Lesioning of nerves, e.g. with phenol or botulinum toxin is widely performed to reduce spastic hypertonus. We have explored the use of direct electrical current (DC) to lesion peripheral nerves. In a series of animal experiments, DC reduced muscle force by controlled amounts and the reduction could last several months. We conclude that in some cases controlled DC lesioning may provide an effective alternative to the less controllable molecular treatments available today.

  7. The Root Pressure Phenomenon

    ERIC Educational Resources Information Center

    Marsh, A. R.

    1972-01-01

    Describes experiments demonstrating that root pressure in plants is probably controlled by a circadian rhythm (biological clock). Root pressure phenomenon plays significant part in water transport in contradiction with prevalent belief. (PS)

  8. Using Square Roots

    ERIC Educational Resources Information Center

    Wilson, William Wynne

    1976-01-01

    This article describes techniques which enable the user of a comparatively simple calculator to perform calculations of cube roots, nth roots, trigonometric, and inverse trigonometric functions, logarithms, and exponentials. (DT)

  9. Vagus Nerve Stimulation for Treating Epilepsy

    MedlinePLUS

    ... Guideline for PATIENTS and their FAMILIES VAGUS NERVE STIMULATION FOR TREATING EPILEPSY This information sheet is provided to help you understand how vagus nerve stimulation (VNS) may help treat epilepsy. The American Academy ...

  10. Infraspinatus muscle atrophy from suprascapular nerve compression.

    PubMed

    Cordova, Christopher B; Owens, Brett D

    2014-02-01

    Muscle weakness without pain may signal a nerve compression injury. Because these injuries should be identified and treated early to prevent permanent muscle weakness and atrophy, providers should consider suprascapular nerve compression in patients with shoulder muscle weakness. PMID:24463748

  11. Low back pain due to hypertrophic roots as presenting symptom of CIDP.

    PubMed

    Di Guglielmo, G; Di Muzio, A; Torrieri, F; Repaci, M; De Angelis, M V; Uncini, A

    1997-10-01

    Attention has recently been drawn to chronic inflammatory demyelinating polyneuropathy (CIDP) with symptomatic nerve root hypertrophy. A 31-year-old woman had fluctuating and worsening low back pain. Absent tendon jerks and a slight weakness of the hand interossei muscles suggested a diffuse neuropathy. The electrophysiological and histological findings were diagnostic for CIDP. Lumbar spine MRI showed marked nerve root enlargement with gadolinium enhancement. This case widens the range of the clinical presentations of CIDP. Further studies are warranted to ascertain whether cauda equina gadolinium enhancement may be a useful tool in the diagnosis of CIDP and a marker of disease activity for monitoring response to therapy. PMID:9412855

  12. Results of ulnar nerve neurotization to biceps brachii muscle in brachial plexus injury

    PubMed Central

    Rezende, Marcelo Rosa De; Rabelo, Neylor Teofilo Araújo; Silveira, Clóvis Castanho; Petersen, Pedro Araújo; Paula, Emygdio José Leomil De; Mattar, Rames

    2012-01-01

    OBJECTIVE: To evaluate the factors influencing the results of ulnar nerve neurotization at the motor branch of the brachii biceps muscle, aiming at the restoration of elbow flexion in patients with brachial plexus injury. METHODS: 19 patients, with 18 men and 1 woman, mean age 28.7 years. Eight patients had injury to roots C5-C6 and 11, to roots C5-C6-C7. The average time interval between injury and surgery was 7.5 months. Four patients had cervical fractures associated with brachial plexus injury. The postoperative follow-up was 15.7 months. RESULTS: Eight patients recovered elbow flexion strength MRC grade 4; two, MRC grade 3 and nine, MRC <3. There was no impairment of the previous ulnar nerve function. CONCLUSION: The surgical results of ulnar nerve neurotization at the motor branch of brachii biceps muscle are dependent on the interval between brachial plexus injury and surgical treatment, the presence of associated fractures of the cervical spine and occipital condyle, residual function of the C8-T1 roots after the injury and the involvement of the C7 root. Signs of reinnervation manifested up to 3 months after surgery showed better results in the long term. Level of Evidence: IV, Case Series. PMID:24453624

  13. Patterned substrates and methods for nerve regeneration

    DOEpatents

    Mallapragada, Surya K.; Heath, Carole; Shanks, Howard; Miller, Cheryl A.; Jeftinija, Srdija

    2004-01-13

    Micropatterned substrates and methods for fabrication of artificial nerve regeneration conduits and methods for regenerating nerves are provided. Guidance compounds or cells are seeded in grooves formed on the patterned substrate. The substrates may also be provided with electrodes to provide electrical guidance cues to the regenerating nerve. The micropatterned substrates give physical, chemical, cellular and/or electrical guidance cues to promote nerve regeneration at the cellular level.

  14. Carbon-nanotube-interfaced glass fiber scaffold for regeneration of transected sciatic nerve.

    PubMed

    Ahn, Hong-Sun; Hwang, Ji-Young; Kim, Min Soo; Lee, Ja-Yeon; Kim, Jong-Wan; Kim, Hyun-Soo; Shin, Ueon Sang; Knowles, Jonathan C; Kim, Hae-Won; Hyun, Jung Keun

    2015-02-01

    Carbon nanotubes (CNTs), with their unique and unprecedented properties, have become very popular for the repair of tissues, particularly for those requiring electrical stimuli. Whilst most reports have demonstrated in vitro neural cell responses of the CNTs, few studies have been performed on the in vivo efficacy of CNT-interfaced biomaterials in the repair and regeneration of neural tissues. Thus, we report here for the first time the in vivo functions of CNT-interfaced nerve conduits in the regeneration of transected rat sciatic nerve. Aminated CNTs were chemically tethered onto the surface of aligned phosphate glass microfibers (PGFs) and CNT-interfaced PGFs (CNT-PGFs) were successfully placed into three-dimensional poly(L/D-lactic acid) (PLDLA) tubes. An in vitro study confirmed that neurites of dorsal root ganglion outgrew actively along the aligned CNT-PGFs and that the CNT interfacing significantly increased the maximal neurite length. Sixteen weeks after implantation of a CNT-PGF nerve conduit into the 10 mm gap of a transected rat sciatic nerve, the number of regenerating axons crossing the scaffold, the cross-sectional area of the re-innervated muscles and the electrophysiological findings were all significantly improved by the interfacing with CNTs. This first in vivo effect of using a CNT-interfaced scaffold in the regeneration process of a transected rat sciatic nerve strongly supports the potential use of CNT-interfaced PGFs at the interface between the nerve conduit and peripheral neural tissues. PMID:25463487

  15. Autoradiographic location of sensory nerve endings in dentin of monkey teeth

    SciTech Connect

    Byers, M.R.; Dong, W.K.

    1983-04-01

    We have used the autoradiographic method to locate trigeminal nerve endings in monkey teeth. The nerve endings were labeled in two adult female Macaca fascicularis by 20 hours of axonal transport of radioactive protein (/sup 3/H-L-proline). We found a few labeled axons in contralateral mandibular central incisors and one mandibular canine. In ipsilateral teeth, numerous myelinated and unmyelinated axons were labeled; they formed a few terminal branches in the roots but primarily branched in the crown to form the peripheral plexus of Raschkow and to terminate as free endings in the odontoblast layer, predentin, and as far as 120 micrometers into dentinal tubules. Electron microscopic autoradiography showed that the radioactive axonally transported protein was confined to sensory axons and endings; odontoblasts and dentin matrix were not significantly labeled. Labeled free nerve endings were closely apposed to odontoblasts in dentin but did not form distinctive junctions with them. Nerve endings were most numerous in the regular tubular dentin of the crown adjacent to the tip of the pulp horn, occurring in at least half of the dentinal tubules there. Our results show tha dentinal sensory nerve endings in primate teeth can be profuse, sparse, or absent depending on the location and structure of dentin and its adjacent pulp. When dentin was innervated, the tubules were straight and contained odontoblast processes, the predentin was wide, the odontoblast cell bodies were relatively columnar, and there was an adjacent cell-free zone and pulpal nerve plexus.

  16. WHY ROOTING FAILS.

    SciTech Connect

    CREUTZ,M.

    2007-07-30

    I explore the origins of the unphysical predictions from rooted staggered fermion algorithms. Before rooting, the exact chiral symmetry of staggered fermions is a flavored symmetry among the four 'tastes.' The rooting procedure averages over tastes of different chiralities. This averaging forbids the appearance of the correct 't Hooft vertex for the target theory.

  17. Corky root rot

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Corky root rot (corchosis) was first reported in Argentina in 1985, but the disease was presumably present long before that. The disease occurs in most alfalfa-growing areas of Argentina but is more common in older stands. In space-planted alfalfa trials scored for root problems, corky root rot was ...

  18. BLACK ROOT ROT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Black Root Rot Prepared by G. S. Abawi, Revised by L.E. Hanson Black root rot is caused by Thielaviopsis basicola (syn. Chalara elegans). The pathogen is widely distributed, can infect more than 130 plant species in 15 families, and causes severe black root rot diseases in ornamentals and crops suc...

  19. Sacral root stimulation for controlled defecation.

    PubMed

    Shafik, A

    1995-01-01

    Selective rectal or sphincter neurostimulation aiming at controlled defecation was performed in 10 dogs. While the dogs were under anesthesia, the rectal and rectal neck pressures, balloon expulsion as well as external anal sphincter (EAS) response to stimulation of the second sacral ventral nerve root (S2) and its autonomic and somatic branches were determined. Each of these nerves was stimulated separately using bipolar platinum cuff electrodes. S2 stimulation resulted in rectal and rectal neck pressure elevation as well as increase of EMG activity of EAS without balloon expulsion. Autonomic branch stimulation effected rectal pressure increase and balloon expulsion, while somatic branch stimulation caused increase of rectal neck pressure and EAS EMG activity with no balloon expulsion. S2 stimulation with somatic branch transection produced rectal pressure elevation and balloon expulsion. In contrast to rectal pressure, the rectal neck pressure increased with increasing stimulus frequency. In conclusion, rectal evacuation and sphincteric control could be induced by selective sacral root electrostimulation: S2 stimulation with transection of the somatic branch for the former and pudendal branch stimulation for the latter. PMID:7890007

  20. Peripheral nerve function in chronic liver disease

    Microsoft Academic Search

    K. N. Seneviratne; O. A. Peiris

    1970-01-01

    Peripheral nerve function has been studied in 50 patients with chronic liver disease. An increase in the latency or a reduction in the response amplitude of the evoked sensory potential of the median nerve was detected in 34 of the 50 subjects. This was in striking contrast to the paucity of neurological signs and symptoms suggestive of peripheral nerve damage

  1. Ephaptic Coupling of Myelinated Nerve S. Binczaka

    E-print Network

    Eilbeck, Chris

    Introduction Following the quantitative formulation of nerve impulse dynamics for the giant axon of the squid fiber; thus the mo- tor nerves of vertebrates--which are about the same diameter as a squid giant axon this picture is appropriate for the squid axon, many nerve fibers are discrete, periodic structures, comprising

  2. Ulnar nerve entrapment syndrome in baseball players

    Microsoft Academic Search

    Wilson Del Pizzo; Frank W. Jobe; Lyle Norwood

    1977-01-01

    Ulnar nerve entrapment at the elbow has been described in the literature. This paper deals with 19 skeletally mature baseball play ers with ulnar nerve entrapment who under went surgery for correction of the problem. The surgery consisted of anterior transfer of the nerve and placement deep to the flexor muscles. Six players quit baseball because of continuing elbow problems,

  3. Cranial Nerves Model - PowerPoint Presentation

    NSDL National Science Digital Library

    Juliann Garza (University of Texas-Pan American Physician Assistant Studies)

    2010-08-16

    Lesson is designed to introduce students to cranial nerves through the use of an introductory lecture. Students will then create a three-dimensional model of the cranial nerves. An information sheet will accompany the model in order to help students learn crucial aspects of the cranial nerves.

  4. Median Nerve as Free Tendon Graft

    Microsoft Academic Search

    1987-01-01

    Four patients are described, all of whom bad tendon injuries in which the median nerve was used as a free tendon graft. Three cases involved the repair of a flexor tendon injury, and one the repair of an extensor tendon. In all cases, reconstruction of the median nerve was performed with a free sural nerve graft. The difficulty was that

  5. Management of optic nerve gliomas

    Microsoft Academic Search

    J. E. Wright; W. I. McDonald; N. B. Call

    1980-01-01

    Seventeen patients thought to have orbital optic nerve gliomas when first seen have been reviewed after up to 12 years. Enlargement of the optic canal was present in 15 of the 16 patients examined, but this finding was unreliable as an indicator of the posterior extent of the tumour. Nine patients had a stable course with little change over a

  6. Reciprocation, Square Root, Inverse Square Root, and Some Elementary Functions

    E-print Network

    Muller, Jean-Michel

    Reciprocation, Square Root, Inverse Square Root, and Some Elementary Functions Using Small with the computation of reciprocals, square roots, inverse square roots, and some elementary functions using small/number of multipliers and compare with other related methods. Index TermsÐReciprocal, square root, inverse square root

  7. Displacement measurement with intracavity interferometry

    NASA Astrophysics Data System (ADS)

    Lazar, Josef; Holá, Miroslava; Fejfar, Antonín.; Stuchlík, Ji?í; Ko?ka, Jan; Oulehla, Jind?ich; ?íp, Ond?ej

    2014-05-01

    We present a measuring technique for displacement and position sensing over a limited range with detection of standingwave pattern inside of a passive Fabry-Perot cavity. The concept considers locking of the laser optical frequency and the length of the Fabry-Perot cavity in resonance. Fixing the length of the cavity to e.g. a highly stable mechanical reference allows to stabilize wavelength of the laser in air and thus to eliminate especially the faster fluctuations of refractive index of air due to air flow and inhomogeneities. Sensing of the interference maxima and minima within the cavity along the beam axis has been tested and proven with a low loss photoresistive photodetector based on a thin polycrystalline silicon layer. Reduction of losses was achieved thanks to a design as an optimized set of interference layers acting as an antireflection coating. The principle is demonstrated on an experimental setup.

  8. Polyimidazoles via aromatic nucleophilic displacement

    NASA Technical Reports Server (NTRS)

    Connell, John W. (inventor); Hergenrother, Paul M. (inventor)

    1992-01-01

    Polyimidazoles (PI) are prepared by the aromatic nucleophilic displacement reaction of di(hydroxyphenyl) imidazole monomers with activated aromatic dihalides or activated aromatic dinitro compounds. The reactions are carried out in polar aprotic solvents such as N,N-dimethyl acetamide, sulfolane, N-methylpyrrolidinone, dimethylsulfoxide, or diphenylsulfone using alkali metal bases such as potassium carbonate at elevated temperatures under nitrogen. The di(hydroxyphenyl) imidazole monomers are prepared by reacting an aromatic aldehyde with a dimethoxybenzil or by reacting an aromatic dialdehyde with a methoxybenzil in the presence of ammonium acetate. The di(methoxyphenyl) imidazole is subsequently treated with aqueous hydrobromic acid to give the di(hydroxphenyl) imidazole monomer. This synthetic route has provided high molecular weight PI of new chemical structure, is economically and synthetically more favorable than other routes, and allows for facile chemical structure variation due to the availability of a large variety of activated aromatic dihalides and dinitro compounds.

  9. Polybenzimidazoles via aromatic nucleophilic displacement

    NASA Technical Reports Server (NTRS)

    Connell, John W. (inventor); Hergenrother, Paul M. (inventor); Smith, Joseph G., Jr. (inventor)

    1995-01-01

    Novel molecular weight controlled and endcapped polybenzimidazoles (PBI) are prepared by the aromatic nucleophilic displacement reaction of di(hydroxyphenyl benzimidazole) monomers with activated aromatic dihalides or activated aromatic dinitro compounds. The PBI are endcapped with mono(hydroxyphenyl) benzimidazoles. The polymerizations are carried out in polar aprotic solvents such as N-methyl-2-pyrrolidinone or N,N-dimethylacetamide using alkali metal bases such as potassium carbonate at elevated temperatures under nitrogen. Mono(hydroxyphenyl) benzimidazoles are synthesizedby reacting phenyl-4-hydroxybenzoate with aromatic (o-diamine)s in diphenylsulfone. Molecular weight controlled and endcapped PBI of new chemical structures are prepared that exhibit a favorable combination of physical and mechanical properties.

  10. Polyimidazoles via aromatic nucleophilic displacement

    NASA Technical Reports Server (NTRS)

    Connell, John W. (Inventor); Hergenrother, Paul M. (Inventor)

    1991-01-01

    Polyimidazoles (Pl) are prepared by the aromatic nucleophilic displacement reaction of di(hydroxyphenyl)imidazole monomers with activated aromatic dihalides or activated aromatic dinitro compounds. The reactions are carried out in polar aprotic solvents such as N,N-dimethylacetamide, sulfolane, N-methylpyrroldinone, dimethylsulfoxide, or diphenylsulfone using alkali metal bases such as potassium carbonate at elevated temperature under nitrogen. The di(hydroxyphenyl)imidazole monomers are prepared by reacting an aromatic aldehyde with a dimethoxybenzil or by reacting an aromatic dialdehyde with a methoxybenzil in the presence of ammonium acetate. The di(methoxyphenyl)imidazole is subsequently treated with aqueous hydrobromic acid to give the di(hydroxyphenyl)imidazole monomer. This synthetic route has provided high molecular weight Pl of new chemical structure, is economically and synthetically more favorable than other routes, and allows for facile chemical structure variation due to the availability of a large variety of activated aromatic dihalides and dinitro compounds.

  11. Polybenzimidazoles Via Aromatic Nucleophilic Displacement

    NASA Technical Reports Server (NTRS)

    Connell, John W. (Inventor); Hergerrother, Paul M. (Inventor); Smith, Joseph G., Jr. (Inventor)

    1997-01-01

    Novel molecular weight controlled and endcapped polybenzimidazoles (PBI) are prepared by the aromatic nucleophilic displacement reaction of di(hydroxyphenylbenzimidazole) monomers with activated aromatic dihalides or activated aromatic dinitro compounds. The PBI are endcapped with mono(hydroxyphenyl)benzimidazoles. The polymerizations are carried out in polar aprotic solvents such as N-methyl-2-pyrrolidinone or N,N-dimethylacetamide using alkali metal bases such as potassium carbonate at elevated temperatures under nitrogen. Mono(hydroxyphenyl)benzimidazoles are synthesized by reacting phenyl-4-hydroxybenzoate with aromatic (o-diamine)s in diphenylsulfone. Molecular weight controlled and endcapped PBI of new chemical structures are prepared that exhibit a favorable combination of physical and mechanical properties.

  12. Variable delivery, fixed displacement pump

    SciTech Connect

    Sommars, Mark F. (Sparland, IL)

    2001-01-01

    A variable delivery, fixed displacement pump comprises a plurality of pistons reciprocated within corresponding cylinders in a cylinder block. The pistons are reciprocated by rotation of a fixed angle swash plate connected to the pistons. The pistons and cylinders cooperate to define a plurality of fluid compression chambers each have a delivery outlet. A vent port is provided from each fluid compression chamber to vent fluid therefrom during at least a portion of the reciprocal stroke of the piston. Each piston and cylinder combination cooperates to close the associated vent port during another portion of the reciprocal stroke so that fluid is then pumped through the associated delivery outlet. The delivery rate of the pump is varied by adjusting the axial position of the swash plate relative to the cylinder block, which varies the duration of the piston stroke during which the vent port is closed.

  13. An ion displacement membrame model.

    PubMed

    Hladky, S B; Harris, J D

    1967-09-01

    The usual assumption in treating the diffusion of ions in an electric field has been that the movement of each ion is independent of the movement of the others. The resulting equation for diffusion by a succession of spontaneous jumps has been well stated by Parlin and Eyring. This paper will consider one simple case in which a different assumption is reasonable. Diffusion of monovalent positive ions is considered as a series of jumps from one fixed negative site to another. The sites are assumed to be full (electrical neutrality). Interaction occurs by the displacement of one ion by another. An ion leaves a site if and only if another ion, not necessarily of the same species, attempts to occupy the same site. Flux ratios and net fluxes are given as functions of the electrical potential, concentration ratios, and number of sites encountered in crossing the membrane. Quantitative comparisons with observations of Hodgkin and Keynes are presented. PMID:6048876

  14. Displaceable Gear Torque Controlled Driver

    NASA Technical Reports Server (NTRS)

    Cook, Joseph S., Jr. (Inventor)

    1997-01-01

    Methods and apparatus are provided for a torque driver including a displaceable gear to limit torque transfer to a fastener at a precisely controlled torque limit. A biasing assembly biases a first gear into engagement with a second gear for torque transfer between the first and second gear. The biasing assembly includes a pressurized cylinder controlled at a constant pressure that corresponds to a torque limit. A calibrated gage and valve is used to set the desired torque limit. One or more coiled output linkages connect the first gear with the fastener adaptor which may be a socket for a nut. A gear tooth profile provides a separation force that overcomes the bias to limit torque at the desired torque limit. Multiple fasteners may be rotated simultaneously to a desired torque limit if additional output spur gears are provided. The torque limit is adjustable and may be different for fasteners within the same fastener configuration.

  15. Fiber optic multimode displacement sensor

    NASA Astrophysics Data System (ADS)

    Fisher, Karl A.; Jarzynski, Jacek

    1996-04-01

    An underwater Optical Motion Sensor (OMS) based on a design first presented by W. B. Spillman, Schlieren multimode fiber-optic hydrophone, Applied Physics Letters 37(2), 15 July 1980, p. 145-146 is described. The displacement sensor uses the same acoustooptical intensity modulation mechanism as Spillman, however the sensing mechanism is isolated from the ambient fluid environment by a small cylindrical aluminum enclosure (1? OD×3/4?). The enclosure contains an inertial mass and the fiber collimators. The inertial mass is suspended in the center of the enclosure by three small wires rigidly mounted to the walls. The mass and wires act as a cantilever beam system with a mechanical resonance near 100 Hz. The transduction mechanism consists of two opposed optical gratings aligned and positioned between the fiber collimators. One grating is mounted on the inertial mass while the other is mounted on the lower end cap of the enclosure. Relative motion between the gratings causes a modulation of the light transmitted through the gratings. The modulated beam is focused onto a photodetector and converted to electric current. The frequency response is flat from 200 Hz-9 kHz with a minimum detectable displacement of 0.002 A and the dynamic range is 136 dB. The small size and light weight give the sensor an effective density of 1.08 g/cm3 making it almost neutrally buoyant in water. This in conjunction with the performance characteristics make this sensor suitable for use in acoustical sensing applications.

  16. Chemically extracted acellular allogeneic nerve graft combined with ciliary neurotrophic factor promotes sciatic nerve repair

    PubMed Central

    Zhang, Yanru; Zhang, Hui; Katiella, Kaka; Huang, Wenhua

    2014-01-01

    A chemically extracted acellular allogeneic nerve graft can reduce postoperative immune rejection, similar to an autologous nerve graft, and can guide neural regeneration. However, it remains poorly understood whether a chemically extracted acellular allogeneic nerve graft combined with neurotrophic factors provides a good local environment for neural regeneration. This study investigated the repair of injured rat sciatic nerve using a chemically extracted acellular allogeneic nerve graft combined with ciliary neurotrophic factor. An autologous nerve anastomosis group and a chemical acellular allogeneic nerve bridging group were prepared as controls. At 8 weeks after repair, sciatic functional index, evoked potential amplitude of the soleus muscle, triceps wet weight recovery rate, total number of myelinated nerve fibers and myelin sheath thickness were measured. For these indices, values in the three groups showed the autologous nerve anastomosis group > chemically extracted acellular nerve graft + ciliary neurotrophic factor group > chemical acellular allogeneic nerve bridging group. These results suggest that chemically extracted acellular nerve grafts combined with ciliary neurotrophic factor can repair sciatic nerve defects, and that this repair is inferior to autologous nerve anastomosis, but superior to chemically extracted acellular allogeneic nerve bridging alone. PMID:25221592

  17. Modelling Toehold-Mediated RNA Strand Displacement

    NASA Astrophysics Data System (ADS)

    Šulc, Petr; Ouldridge, Thomas E.; Romano, Flavio; Doye, Jonathan P. K.; Louis, Ard A.

    2015-03-01

    We study the thermodynamics and kinetics of an RNA toehold-mediated strand displacement reaction with a recently developed coarse-grained model of RNA. Strand displacement, during which a single strand displaces a different strand previously bound to a complementary substrate strand, is an essential mechanism in active nucleic acid nanotechnology and has also been hypothesized to occur in vivo. We study the rate of displacement reactions as a function of the length of the toehold and temperature and make two experimentally testable predictions: that the displacement is faster if the toehold is placed at the 5' end of the substrate and that the displacement slows down with increasing temperature for longer toeholds.

  18. Modelling toehold-mediated RNA strand displacement.

    PubMed

    Šulc, Petr; Ouldridge, Thomas E; Romano, Flavio; Doye, Jonathan P K; Louis, Ard A

    2015-03-10

    We study the thermodynamics and kinetics of an RNA toehold-mediated strand displacement reaction with a recently developed coarse-grained model of RNA. Strand displacement, during which a single strand displaces a different strand previously bound to a complementary substrate strand, is an essential mechanism in active nucleic acid nanotechnology and has also been hypothesized to occur in vivo. We study the rate of displacement reactions as a function of the length of the toehold and temperature and make two experimentally testable predictions: that the displacement is faster if the toehold is placed at the 5' end of the substrate; and that the displacement slows down with increasing temperature for longer toeholds. PMID:25762335

  19. Modelling toehold-mediated RNA strand displacement

    E-print Network

    Petr Šulc; Thomas E. Ouldridge; Flavio Romano; Jonathan P. K. Doye; Ard A. Louis

    2014-11-12

    We study the thermodynamics and kinetics of an RNA toehold-mediated strand displacement reaction with a recently developed coarse-grained model of RNA. Strand displacement, during which a single strand displaces a different strand previously bound to a complementary substrate strand, is an essential mechanism in active nucleic acid nanotechnology and has also been hypothesized to occur in vivo. We study the rate of displacement reactions as a function of the length of the toehold and temperature and make two experimentally testable predictions: that the displacement is faster if the toehold is placed at the 5' end of the substrate and that the displacement slows down with increasing temperature for longer toeholds.

  20. Pharmacology of airway afferent nerve activity

    PubMed Central

    Undem, Bradley J; Carr, Michael J

    2001-01-01

    Afferent nerves in the airways serve to regulate breathing pattern, cough, and airway autonomic neural tone. Pharmacologic agents that influence afferent nerve activity can be subclassified into compounds that modulate activity by indirect means (e.g. bronchial smooth muscle spasmogens) and those that act directly on the nerves. Directly acting agents affect afferent nerve activity by interacting with various ion channels and receptors within the membrane of the afferent terminals. Whether by direct or indirect means, most compounds that enter the airspace will modify afferent nerve activity, and through this action alter airway physiology. PMID:11686889

  1. Morphological studies of the vestibular nerve

    NASA Technical Reports Server (NTRS)

    Bergstroem, B.

    1973-01-01

    The anatomy of the intratemporal part of the vestibular nerve in man, and the possible age related degenerative changes in the nerve were studied. The form and structure of the vestibular ganglion was studied with the light microscope. A numerical analysis of the vestibular nerve, and caliber spectra of the myelinated fibers in the vestibular nerve branches were studied in individuals of varying ages. It was found that the peripheral endings of the vestibular nerve form a complicated pattern inside the vestibular sensory epithelia. A detailed description of the sensory cells and their surface organelles is included.

  2. Leptin-sensitive sensory nerves innervate white fat

    PubMed Central

    Murphy, Keegan T.; Schwartz, Gary J.; Nguyen, Ngoc Ly T.; Mendez, Jennifer M.; Ryu, Vitaly

    2013-01-01

    Leptin, the primary white adipose tissue (WAT) adipokine, is thought to convey lipid reserve information to the brain via the circulation. Because WAT responds to environmental/internal signals in a fat pad-specific (FPS) manner, systemic signals such as leptin would fail to communicate such distinctive information. Saturation of brain leptin transport systems also would fail to convey increased lipid levels beyond that point. WAT possesses sensory innervation exemplified by proven sensory-associated peptides in nerves within the tissue and by viral sensory nerve-specific transneuronal tract tracer, H129 strain of herpes simplex virus 1 labeling of dorsal root ganglia (DRG) pseudounipolar neurons, spinal cord and central sensory circuits. Leptin as a paracrine factor activating WAT sensory innervation could supply the brain with FPS information. Therefore, we tested for and found the presence of the long form of the leptin receptor (Ob-Rb) on DRG pseudounipolar neurons immunohistochemically labeled after injections of Fluorogold, a retrograde tract tracer, into inguinal WAT (IWAT). Intra-IWAT leptin injections (300 ng) significantly elevated IWAT nerve spike rate within 5 min and persisted for at least 30 min. Intra-IWAT leptin injections also induced significant c-Fos immunoreactivity (ir), indicating neural activation across DRG pseudounipolar sensory neurons labeled with Fluorogold IWAT injections. Intraperitoneal leptin injection did not increase c-Fos-ir in DRG or the arcuate nucleus, nor did it increase arcuate signal transducer and activator of transcription 3 phosphorylation-ir. Collectively, these results strongly suggest that endogenous leptin secreted from white adipocytes functions as a paracrine factor to activate spinal sensory nerves innervating the tissue. PMID:23612999

  3. Displacement speeds in turbulent premixed flame simulations

    SciTech Connect

    Day, Marcus S.; Shepherd, Ian G.; Bell, J.; Grcar, Joseph F.; Lijewski, Michael J.

    2007-07-01

    The theory of turbulent premixed flames is based on acharacterization of the flame as a discontinuous surface propagatingthrough the fluid. The displacement speed, defined as the local speed ofthe flame front normal to itself, relative to the unburned fluid,provides one characterization of the burning velocity. In this paper, weintroduce a geometric approach to computing displacement speed anddiscuss the efficacy of the displacement speed for characterizing aturbulent flame.

  4. An improved displacement damage monitor LED

    Microsoft Academic Search

    A. L. Barry; R. Maxseiner; R. Wojcik; M. A. Briere; D. Braeunig

    1990-01-01

    A frequency-domain technique for measuring carrier lifetime in GaAs light-emitting-diode (LED) displacement damage monitors capable of high sensitivity and repeatability is developed. Applications of this technique that take advantage of the high sensitivity of this method, including the measurement of the threshold energy for lattice displacement in GaAs, are described. The measured minimum electron energy for displacement damage was 270±15

  5. Facial nerve demyelination and vascular compression are both needed to induce facial hyperactivity: A study in rats

    Microsoft Academic Search

    A. Kuroki; A. R. Møller

    1994-01-01

    Summary It is generally assumed that hemifacial spasm (HFS) is caused by vascular compression of the facial nerve at the root exit zone (REZ), but the mechanism for the development of HFS is not known. Evidence has been previously presented that the signs of HFS are caused by hyperactivity of the facial motonucleus that is caused by the irritation to

  6. Identifying motor and sensory myelinated axons in rabbit peripheral nerves by histochemical staining for carbonic anhydrase and cholinesterase activities

    NASA Technical Reports Server (NTRS)

    Riley, Danny A.; Sanger, James R.; Matloub, Hani S.; Yousif, N. John; Bain, James L. W.

    1988-01-01

    Carbonic anhydrase (CA) and cholinesterase (CE) histochemical staining of rabbit spinal nerve roots and dorsal root ganglia demonstrated that among the reactive myeliated axons, with minor exceptions, sensory axons were CA positive and CE negative whereas motor axons were CA negative and CE positive. The high specificity was achieved by adjusting reaction conditions to stain subpopulations of myelinated axons selectively while leaving 50 percent or so unstained. Fixation with glutaraldehyde appeared necessary for achieving selectivity. Following sciatic nerve transection, the reciprocal staining pattern persisted in damaged axons and their regenerating processes which formed neuromas within the proximal nerve stump. Within the neuromas, CA-stained sensory processes were elaborated earlier and in greater numbers than CE-stained regenerating motor processes. The present results indicate that histochemical axon typing can be exploited to reveal heterogeneous responses of motor and sensory axons to injury.

  7. Designing ideal conduits for peripheral nerve repair

    PubMed Central

    de Ruiter, Godard C. W.; Malessy, Martijn J. A.; Yaszemski, Michael J.; Windebank, Anthony J.; Spinner, Robert J.

    2010-01-01

    Nerve tubes, guides, or conduits are a promising alternative for autologous nerve graft repair. The first biodegradable empty single lumen or hollow nerve tubes are currently available for clinical use and are being used mostly in the repair of small-diameter nerves with nerve defects of < 3 cm. These nerve tubes are made of different biomaterials using various fabrication techniques. As a result these tubes also differ in physical properties. In addition, several modifications to the common hollow nerve tube (for example, the addition of Schwann cells, growth factors, and internal frameworks) are being investigated that may increase the gap that can be bridged. This combination of chemical, physical, and biological factors has made the design of a nerve conduit into a complex process that demands close collaboration of bioengineers, neuroscientists, and peripheral nerve surgeons. In this article the authors discuss the different steps that are involved in the process of the design of an ideal nerve conduit for peripheral nerve repair. PMID:19435445

  8. Nerve conduction studies in early tuberculoid leprosy

    PubMed Central

    Vashisht, Deepak; Das, Arjun Lal; Vaishampayan, Sanjeev S; Vashisht, Surbhi; Joshi, Rajneesh

    2014-01-01

    Context: Hansen's disease is a chronic illness; besides involving skin and peripheral nerves, it affects multiple organs. Nerve involvement is always present in leprosy, and it may be present much before the patient manifests clinically. Aims: To assess nerve conduction parameters in thickened and contralateral non-thickened nerves in early tuberculoid leprosy Materials and Methods: Fifty new untreated male patients with tuberculoid and borderline tuberculoid leprosy in the age group of 15-50 years with thickened peripheral nerves on one side were included in the study. Nerve conduction studies consisting of sensory and motor velocity (NCV), distal latencies, and amplitude were carried out on thickened ulnar, common peroneal, and posterior tibial nerves and contralateral normal nerves. Statistical Analysis Used: Mean values along with coefficient of variation were obtained for various parameters. These were compared with normal values of the control population. P value was used to verify statistical significance. Results: Nerve conduction parameters were deranged in most of the thickened nerves. Sensory parameters were affected early in the disease process. Conclusion: Additional parameters are required to assess nerve damage in early cases, where it is more in slow conducting fibers (average velocity fibers). Change in conduction velocity may not be marked; this calls for the measurement of fast fibers separately because potentials recorded are mainly from myelinated fibers. PMID:25593812

  9. Expression patterns of erythropoietin and its receptor in the developing spinal cord and dorsal root ganglia

    Microsoft Academic Search

    Wolfgang Knabe; Anna-Leena Sirén; Hannelore Ehrenreich; Hans-Jürg Kuhn

    2005-01-01

    Recombinant human erythropoietin (EPO) is neuroprotective in animal models of adult spinal cord injury, and reduces apoptosis\\u000a in adult dorsal root ganglia after spinal nerve crush. The present work demonstrates that spinal cord and dorsal root ganglia\\u000a share dynamic expression patterns of EPO and its receptor (EPOR) during development. C57Bl mice from embryonic days (E) 8\\u000a (E8) to E19 were

  10. A Method for µCT Based Assessment of Root Canal Instrumentation in Endodontics Research

    Microsoft Academic Search

    Johan Van Cleynenbreugel; Lars Bergmans; Martine Wevers; Paul Lambrechts

    2001-01-01

    The field of dendodontics is devoted to the study and treatment of tissues inside (endo) the tooth (dontia). When a nerve\\u000a within a tooth becomes necrotic and\\/or infected, so-called root canal therapy might be considered. In this case, a dental\\u000a practitioner cleans and widens the inner root canal system by chemical irrigation and mechanical instrumentation with respect\\u000a to the original

  11. Solitary fibrous tumor of the spinal nerve rootlet: report of a case mimicking schwannoma.

    PubMed

    Piana, Simonetta; Putrino, Innocenza; Cavazza, Alberto; Nigrisoli, Evandro

    2004-03-01

    We report a case of solitary fibrous tumor involving the spinal nerve root at the L1-L2 level in a 67-year-old man. The patient presented with lumbar pain and weakness in his right lower extremity. Histologically, the tumor was composed of a proliferation of monomorphous spindle cells in an abundant collagenous stroma; neither necrosis nor mitoses were evident. These cells were strongly immunoreactive with CD34, Bcl-2, CD99, and vimentin, but were negative with S100 protein, smooth muscle actin, and epithelial membrane antigen. Such an immunohistochemical profile was consistent with a solitary fibrous tumor of the spinal nerve rootlet and ruled out the main differential diagnoses, schwannoma and meningioma. The present case suggests that solitary fibrous tumor should be considered in differentiating spindle cell lesions of the spinal cord and nerve rootlet. PMID:14987150

  12. Myelinated sensory and alpha motor axon regeneration in peripheral nerve neuromas

    NASA Technical Reports Server (NTRS)

    Macias, M. Y.; Lehman, C. T.; Sanger, J. R.; Riley, D. A.

    1998-01-01

    Histochemical staining for carbonic anhydrase and cholinesterase (CE) activities was used to analyze sensory and motor axon regeneration, respectively, during neuroma formation in transected and tube-encapsulated peripheral nerves. Median-ulnar and sciatic nerves in the rodent model permitted testing whether a 4 cm greater distance of the motor neuron soma from axotomy site or intrinsic differences between motor and sensory neurons influenced regeneration and neuroma formation 10, 30, and 90 days later. Ventral root radiculotomy confirmed that CE-stained axons were 97% alpha motor axons. Distance significantly delayed axon regeneration. When distance was negligible, sensory axons grew out sooner than motor axons, but motor axons regenerated to a greater quantity. These results indicate regeneration differences between axon subtypes and suggest more extensive branching of motor axons within the neuroma. Thus, both distance from injury site to soma and inherent motor and sensory differences should be considered in peripheral nerve repair strategies.

  13. Inferior alveolar nerve damage because of overextended endodontic material: a problem of sealer cement biocompatibility?

    PubMed

    Escoda-Francoli, Jaume; Canalda-Sahli, Carles; Soler, Albert; Figueiredo, Rui; Gay-Escoda, Cosme

    2007-12-01

    Damage to the inferior alveolar nerve is a relatively infrequent complication in dental practice. When root canal treatment of a lower molar or premolar surpasses and/or overextends beyond the apical foramen and invades the periapical zone, the foreign material introduced within such a sensitive anatomical space may mechanically or even chemically affect the inferior alveolar nerve. We describe a case of endodontic treatment of a permanent right lower first molar in which the sealer cement overextended in large amounts and damaged the right inferior alveolar nerve. The condition reverted a few months after the surgical removal of the material. Evaluation of the removed material, using powder x-ray diffraction and scanning electron microscopy with coupled dispersive energy spectroscopy, showed it to consist of calcium tungstate (scheelite [CaWO4]) and zirconium oxide (baddeleyite [ZrO2]), which were chemical components of the sealer cement. PMID:18037065

  14. Implant Injury Case Series and Review of the Literature Part 1: Inferior alveolar nerve injury.

    PubMed

    Du Toit, Jonathan; Gluckman, Howard; Gamil, Rami; Renton, Tara

    2014-06-19

    Abstract ABSTRACTInjury to adjacent structures is an unfortunate and avoidable outcome of oral implant placement surgery. Paramount among these is perforation; either in to paranasal sinus, neighbouring tooth root, through cortical plate, into vessels, canals, and most importantly nerves. Injudicious oral implant placement can be attributed in most cases to poor treatment planning. We present several cases, referred for post-surgical radiology, illustrating injury to the inferior alveolar canal, by implant impingement, penetration, and even complete obliteration of the nerve and canal, in the absence of proper treatment planning and imaging modalities. The authors stress the importance of thorough implant case preparation and planning which may include the use of cone beam computed tomography, in order to minimize nerve injury. PMID:24945089

  15. Free vascularized deep peroneal nerve grafts.

    PubMed

    Koshima, I; Okumoto, K; Umeda, N; Moriguchi, T; Ishii, R; Nakayama, Y

    1996-04-01

    An ideal donor site for vascularized nerve grafts should have a constant anatomy, minimal functional loss after the nerve has been sacrificed, and a dependable blood supply parallel to the nerve over a relatively long distance. Creating a pedicle for a free vascularized deep peroneal nerve graft with the anterior tibial vessels seems to be a most suitable method for repairing long nerve gaps of over 20 cm and digital nerve defects with severe finger damage. Applications of this nerve graft to digital nerve losses with severely scarred beds created by avulsion injury, and two-stage reconstruction in some partial brachial plexus palsies (free vascularized nerve graft in the first stage and free vascularized muscle graft in the second stage) are well indicated. Advantages of this technique are: (1) A long nerve graft (up to 25 cm) can be obtained, and anomalies are rare (the nerve is absent in only 4 percent of cases). (2) The caliber of the vascular pedicle is large (approximately equal to 3 mm). (3) The nerve has a sufficient blood supply from the collateral blood vessels. (4) The graft can be easily obtained in the supine position. (5) A monitoring skin flap, based on the inferior lateral peroneal artery, can be attached to the nerve graft. (6) Sensory loss resulting from the sacrifice of the nerve covers a minimal area. (7) A donor scar on the anterior aspect of the lower leg is more acceptable than one on the posterior aspect because of less movement in walking. Disadvantages of this technique are: (1) Sacrifice of the large vessels in the lower leg may result in circulatory complications in the donor foot; to avoid this problem, preoperative angiography is recommended. (2) The donor scar is in an exposed area in female patients. (3) There may be temporary postoperative edema and disability in the donor leg. PMID:8726331

  16. Mapping the entire human corneal nerve architecture

    PubMed Central

    He, Jiucheng; Bazan, Nicolas G.; Bazan, Haydee E.P.

    2010-01-01

    We developed an approach to generate a three-dimensional map that facilitates the assessment of epithelial nerve density in different corneal areas to define aging and gender influence on human corneal nerve architecture. Twenty-eight fresh human eyes from 14 donors of different ages were studied. Corneal nerves were stained and consecutive images acquired with a fluorescence microscope, recorded at the same plane, and merged for viewing the complete epithelial and stromal nerve architecture. After whole mount examination, the same cornea was also used for transection. Stromal nerves entered the cornea in a radial pattern, subsequently dividing into smaller branches. Some branches connected at the center of the stroma, but most penetrated upward into the epithelium. No differences were observed between nerve densities in the four corneal quadrants. Epithelial innervation in the limbal and most of the peripheral area was supplied by a superficial network surrounding the limbal area. Central epithelial nerves were supplied by branches of the stromal nerve network. Epithelial nerve density and terminal numbers were higher in the center of the cornea, rather than the periphery. There were no differences in epithelial nerve density between genders, but there was a progressive nerve density reduction concomitant with aging, mainly in eye samples of donors 70-years of age and older. The modified technique of tissue preparation used for this study allowed for observation of new nerve structure features and, for the first time, provided a complete view of the human corneal nerve architecture. Our study reveals that aging decreases the number of central epithelial nerve terminals, and increases the presence of irregular anomalies beneath the basal layer. PMID:20650270

  17. Nerve sheath ganglion of the tibial nerve presenting as a Baker's cyst: a case report.

    PubMed

    Tseng, Kuo-Fung; Hsu, Horng-Chaung; Wang, Fu-Cheng; Fong, Yi-Chin

    2006-09-01

    Nerve sheath ganglion is a relatively rare clinical entity commonly found in the peroneal nerve in the lower limb or the ulnar nerve in the upper extremity. It is rarely found in the tibial nerve. The occurrence of a nerve sheath ganglion in a patient's tibial nerve has been identified. The initial presentation of the tumor mass has been very similar to that of a Baker's cyst, namely a soft undulating popliteal mass. Yet, the case also presented symptoms and signs of tibial nerve compressive neuropathy. We present here a rare case of nerve sheath ganglion of the tibial nerve. Clinical courses of the patient were reviewed, and relevant issues were discussed with a thorough literature review. PMID:16570194

  18. Displacement based multilevel structural optimization

    NASA Technical Reports Server (NTRS)

    Striz, Alfred G.

    1995-01-01

    Multidisciplinary design optimization (MDO) is expected to play a major role in the competitive transportation industries of tomorrow, i.e., in the design of aircraft and spacecraft, of high speed trains, boats, and automobiles. All of these vehicles require maximum performance at minimum weight to keep fuel consumption low and conserve resources. Here, MDO can deliver mathematically based design tools to create systems with optimum performance subject to the constraints of disciplines such as structures, aerodynamics, controls, etc. Although some applications of MDO are beginning to surface, the key to a widespread use of this technology lies in the improvement of its efficiency. This aspect is investigated here for the MDO subset of structural optimization, i.e., for the weight minimization of a given structure under size, strength, and displacement constraints. Specifically, finite element based multilevel optimization of structures (here, statically indeterminate trusses and beams for proof of concept) is performed. In the system level optimization, the design variables are the coefficients of assumed displacement functions, and the load unbalance resulting from the solution of the stiffness equations is minimized. Constraints are placed on the deflection amplitudes and the weight of the structure. In the subsystems level optimizations, the weight of each element is minimized under the action of stress constraints, with the cross sectional dimensions as design variables. This approach is expected to prove very efficient, especially for complex structures, since the design task is broken down into a large number of small and efficiently handled subtasks, each with only a small number of variables. This partitioning will also allow for the use of parallel computing, first, by sending the system and subsystems level computations to two different processors, ultimately, by performing all subsystems level optimizations in a massively parallel manner on separate processors. It is expected that the subsystems level optimizations can be further improved through the use of controlled growth, a method which reduces an optimization to a more efficient analysis with only a slight degradation in accuracy. The efficiency of all proposed techniques is being evaluated relative to the performance of the standard single level optimization approach where the complete structure is weight minimized under the action of all given constraints by one processor and to the performance of simultaneous analysis and design which combines analysis and optimization into a single step. It is expected that the present approach can be expanded to include additional structural constraints (buckling, free and forced vibration, etc.) or other disciplines (passive and active controls, aerodynamics, etc.) for true MDO.

  19. Nerve guides manufactured from photocurable polymers to aid peripheral nerve repair.

    PubMed

    Pateman, Christopher J; Harding, Adam J; Glen, Adam; Taylor, Caroline S; Christmas, Claire R; Robinson, Peter P; Rimmer, Steve; Boissonade, Fiona M; Claeyssens, Frederik; Haycock, John W

    2015-05-01

    The peripheral nervous system has a limited innate capacity for self-repair following injury, and surgical intervention is often required. For injuries greater than a few millimeters autografting is standard practice although it is associated with donor site morbidity and is limited in its availability. Because of this, nerve guidance conduits (NGCs) can be viewed as an advantageous alternative, but currently have limited efficacy for short and large injury gaps in comparison to autograft. Current commercially available NGC designs rely on existing regulatory approved materials and traditional production methods, limiting improvement of their design. The aim of this study was to establish a novel method for NGC manufacture using a custom built laser-based microstereolithography (?SL) setup that incorporated a 405 nm laser source to produce 3D constructs with ?50 ?m resolution from a photocurable poly(ethylene glycol) resin. These were evaluated by SEM, in vitro neuronal, Schwann and dorsal root ganglion culture and in vivo using a thy-1-YFP-H mouse common fibular nerve injury model. NGCs with dimensions of 1 mm internal diameter × 5 mm length with a wall thickness of 250 ?m were fabricated and capable of supporting re-innervation across a 3 mm injury gap after 21 days, with results close to that of an autograft control. The study provides a technology platform for the rapid microfabrication of biocompatible materials, a novel method for in vivo evaluation, and a benchmark for future development in more advanced NGC designs, biodegradable and larger device sizes, and longer-term implantation studies. PMID:25725557

  20. Combination of Acellular Nerve Graft and Schwann Cells-Like Cells for Rat Sciatic Nerve Regeneration

    PubMed Central

    Gao, Songtao; Zheng, Yan; Cai, Qiqing; Deng, Zhansheng; Yao, Weitao; Wang, Jiaqiang; Wang, Xin; Zhang, Peng

    2014-01-01

    Objective. To investigate the effect of tissue engineering nerve on repair of rat sciatic nerve defect. Methods. Forty-five rats with defective sciatic nerve were randomly divided into three groups. Rats in group A were repaired by acellular nerve grafts only. Rats in group B were repaired by tissue engineering nerve. In group C, rats were repaired by autogenous nerve grafts. After six and twelve weeks, sciatic nerve functional index (SFI), neural electrophysiology (NEP), histological and transmission electron microscope observation, recovery ratio of wet weight of gastrocnemius muscle, regenerated myelinated nerve fibers number, nerve fiber diameter, and thickness of the myelin sheath were measured to assess the effect. Results. After six and twelve weeks, the recovery ratio of SFI and wet weight of gastrocnemius muscle, NEP, and the result of regenerated myelinated nerve fibers in groups B and C were superior to that of group A (P < 0.05), and the difference between groups B and C was not statistically significant (P > 0.05). Conclusion. The tissue engineering nerve composed of acellular allogenic nerve scaffold and Schwann cells-like cells can effectively repair the nerve defect in rats and its effect was similar to that of the autogenous nerve grafts. PMID:25114806

  1. Neuromodulatory nerve regeneration: adipose tissue-derived stem cells and neurotrophic mediation in peripheral nerve regeneration.

    PubMed

    Widgerow, Alan D; Salibian, Ara A; Lalezari, Shadi; Evans, Gregory R D

    2013-12-01

    Peripheral nerve injury requiring nerve gap reconstruction remains a major problem. In the quest to find an alternative to autogenous nerve graft procedures, attempts have been made to differentiate mesenchymal stem cells into neuronal lineages in vitro and utilize these cellular constructs for nerve regeneration. Unfortunately, this has produced mixed results, with no definitive procedure matching or surpassing traditional nerve grafting procedures. This review presents a different approach to nerve regeneration. The literature was reviewed to evaluate current methods of using adipose-derived stem cells (ADSCs) for peripheral nerve regeneration in in vivo models of animal peripheral nerve injury. The authors present cited evidence for directing nerve regeneration through paracrine effects of ADSCs rather than through in vitro nerve regeneration. The paracrine effects rely mainly, but not solely, on the elaboration of nerve growth factors and neurotrophic mediators that influence surrounding host cells to orchestrate in vivo nerve regeneration. Although this paradigm has been indirectly referred to in a host of publications, few major efforts for this type of neuromodulatory nerve regeneration have been forthcoming. The ADSCs are initially "primed" in vitro using specialized controlled medium (not for neuronal differentiation but for sustainability) and then incorporated into a hydrogel base matrix designed for this purpose. This core matrix is then introduced into a natural collagen-based nerve conduit. The prototype design concepts, evidence for paracrine influences, and regulatory hurdles that are avoided using this approach are discussed. PMID:24105674

  2. Use of ultrasonography in ulnar nerve entrapment surgery--a prospective study.

    PubMed

    Kutlay, Murat; Colak, Ahmet; Sim?ek, Hakan; Oztürk, Ersin; Senol, Mehmet Güney; Topuz, Kivanç; Demircan, Mehmet Nusret

    2009-04-01

    The purpose of our study is to assess the usefulness of high-resolution ultrasonography in observing the morphology and dynamics of the ulnar nerve in the cubital tunnel and also the efficacy of ultrasonography in a more accurate diagnosis and appropriate surgical treatment decision. Cross-sectional area of the ulnar nerves of 40 healthy volunteers in the control group were measured bilaterally at the level of the epicondyle, 2 cm proximal to and 2 cm distal to the epicondyle. Measurements were obtained for elbows both in extension and flexion. Then, we prospectively obtained the cross-sectional area values of 18 patients at the same levels, elbows in extension and flexion position, and compared the data obtained from the patient group and the control group. The differences between the cross-sectional areas of the ulnar nerves in extension and flexion were statistically significant in the patient population (p < 0.001). Mean cross-sectional area of the ulnar nerve in the patient population was calculated as 0.16 cm(2), and we accepted the cut-off point as 0.1 cm(2). This value for cross-sectional area yielded a sensitivity of 90% and a specificity of 100% in diagnosis of ulnar nerve entrapment. Results substantiated conspicuous morphological changes in ulnar nerve during flexion and extension of the elbow. We also observed that as the degree of the nerve displacement by virtue of elbow flexion that is discerned by ultrasonography increased, a more aggressive decompressive surgery was needed for an appropriate treatment. PMID:18797947

  3. Effects of Fault Displacement on Emplacement Drifts

    SciTech Connect

    F. Duan

    2000-04-25

    The purpose of this analysis is to evaluate potential effects of fault displacement on emplacement drifts, including drip shields and waste packages emplaced in emplacement drifts. The output from this analysis not only provides data for the evaluation of long-term drift stability but also supports the Engineered Barrier System (EBS) process model report (PMR) and Disruptive Events Report currently under development. The primary scope of this analysis includes (1) examining fault displacement effects in terms of induced stresses and displacements in the rock mass surrounding an emplacement drift and (2 ) predicting fault displacement effects on the drip shield and waste package. The magnitude of the fault displacement analyzed in this analysis bounds the mean fault displacement corresponding to an annual frequency of exceedance of 10{sup -5} adopted for the preclosure period of the repository and also supports the postclosure performance assessment. This analysis is performed following the development plan prepared for analyzing effects of fault displacement on emplacement drifts (CRWMS M&O 2000). The analysis will begin with the identification and preparation of requirements, criteria, and inputs. A literature survey on accommodating fault displacements encountered in underground structures such as buried oil and gas pipelines will be conducted. For a given fault displacement, the least favorable scenario in term of the spatial relation of a fault to an emplacement drift is chosen, and the analysis is then performed analytically. Based on the analysis results, conclusions are made regarding the effects and consequences of fault displacement on emplacement drifts. Specifically, the analysis will discuss loads which can be induced by fault displacement on emplacement drifts, drip shield and/or waste packages during the time period of postclosure.

  4. Feasibility of Nerve Stimulator as a Supplemental Aid for Lumbar Transforaminal Epidural Block

    PubMed Central

    Kim, Dae Hee; Lim, Chae Hyun; Heo, Ju Yeong; Jang, Young Jae

    2014-01-01

    Background The purpose of this study was to evaluate the clinical feasibility of an electric nerve stimulator in a lumbar transforaminal epidural block. Methods Using an electric nerve stimulator, transforaminal epidural blocks were performed in 105 segments of 49 patients who presented with lower back pain with radiating pain to lower extremities. The contrast medium was injected to delineate the nerve root after positioning an insulated needle at the intervertebral foramen under fluoroscopic guidance. Then, the nerve root was electrically stimulated with the insulated needle to confirm whether or not the same radiating pain was evoked. Results Of the 105 foraminal segments, the same radiating pain was evoked at 0.5 mAh in 47 segments (44.8%), at 1.0 mAh in 22 (21.0%), at 1.5 mAh in 3 (2.9%), at 2.0 mAh in 15 (14.3%), at 2.5 mAh in 4 (3.8%), and at 3.0 mAh in 5 (4.8%). No response was observed in 9 segments (8.6%). The fluoroscopy revealed successful positioning of the needle in the patients with an evoked radiating pain over 2.0 mAh. The visual analogue scale (VAS) obtained for pain improved from a mean of 7.5 to 2.7 after the block (p = 0.001). In the 9 cases without response to electrical stimulation, the patients showed an improvement on VAS from 7.8 to 3.4 (p= 0.008) also. Conclusions A nerve stimulator can help to predict the accuracy of needle positioning as a supplemental aid for a successful lumbar transforaminal epidural block. It is sufficient to initiate a proper stimulation amplitude of the nerve at 2 mAh. PMID:25177459

  5. Tooth Eruption without Roots

    PubMed Central

    2013-01-01

    Root development and tooth eruption are very important topics in dentistry. However, they remain among the less-studied and -understood subjects. Root development accompanies rapid tooth eruption, but roots are required for the movement of teeth into the oral cavity. It has been shown that the dental follicle and bone remodeling are essential for tooth eruption. So far, only limited genes have been associated with root formation and tooth eruption. This may be due to the difficulties in studying late stages of tooth development and tooth movement and the lack of good model systems. Transgenic mice with eruption problems and short or no roots can be used as a powerful model for further deciphering of the cellular, molecular, and genetic mechanisms underlying root formation and tooth eruption. Better understanding of these processes can provide hints on delivering more efficient dental therapies in the future. PMID:23345536

  6. Root canal irrigants

    PubMed Central

    Kandaswamy, Deivanayagam; Venkateshbabu, Nagendrababu

    2010-01-01

    Successful root canal therapy relies on the combination of proper instrumentation, irrigation, and obturation of the root canal. Of these three essential steps of root canal therapy, irrigation of the root canal is the most important determinant in the healing of the periapical tissues. The primary endodontic treatment goal must thus be to optimize root canal disinfection and to prevent reinfection. In this review of the literature, various irrigants and the interactions between irrigants are discussed. We performed a Medline search for English-language papers published untill July 2010. The keywords used were ‘root canal irrigants’ and ‘endodontic irrigants.’ The reference lists of each article were manually checked for additional articles of relevance. PMID:21217955

  7. Surgical management of the severely displaced supracondylar fracture of the humerus in children.

    PubMed

    Kumar, Ritabh; Kiran, E Krishna; Malhotra, Rajesh; Bhan, S

    2002-07-01

    We reviewed 44 children with a widely displaced supracondylar fracture of the humerus (Gartland grade III) treated with primary open reduction and cross pinning. The average age was 8 years and the mean delay in presentation was 34 h. Comminution of the medial supracondylar pillar was seen in 57% of the cases. After treatment, the range of the elbow motion was restricted in eight patients. Cubitus varus was not seen. There was no deep infection or myositis ossificans. Post-operatively, five children had a temporary nerve palsy. According to Flynns' criteria, 42 patients had a satisfactory outcome. PMID:12098550

  8. Miniarthrotomy assisted percutaneous screw fixation for displaced medial malleolus fractures – A novel technique

    PubMed Central

    Saini, Pramod; Aggrawal, Abhinav; Meena, Sanjay; Trikha, Vivek; Mittal, Samarth

    2014-01-01

    Aim To describe here a technique of miniarthrotomy assisted percutaneous screw insertion for displaced Herscovici type B and C medial malleolar fractures. Method Incision was made centred over the superomedial angle of the ankle mortise, about half a cm medial to tibialis anterior. Arthrotomy was done and reduction obtained. Percuntaneously, two 4 mm cancellous cannulated screws were inserted through medial malleolus. Results and conclusion This approach allows direct visualization of reduction, removal of entrapped soft tissue and preservation of saphenous vein and nerve.

  9. Expression of p-Akt in Sensory Neurons and Spinal Cord after Peripheral Nerve Injury

    Microsoft Academic Search

    Tie-Jun Sten Shi; Ping Huang; Jan Mulder; Sandra Ceccatelli; Tomas Hökfelt

    2009-01-01

    Akt has been implicated in pro-survival and anti-apoptotic activities in many cell types, including dorsal root ganglion (DRG) and spinal motor neurons. In this immunohistochemical study we have monitored phosphorylated Akt (p-Akt) levels in adult mouse DRGs and spinal cord following unilateral peripheral sciatic nerve transection (axotomy) or carrageenan-induced inflammation. In control animals around half of the lumbar DRG neuron

  10. Synaptic reorganization in the substantia gelatinosa after peripheral nerve neuroma formation: aberrant innervation of lamina II neurons by Abeta afferents.

    PubMed

    Kohama, I; Ishikawa, K; Kocsis, J D

    2000-02-15

    Intracellular recording and extracellular field potential (FP) recordings were obtained from spinal cord dorsal horn neurons (laminae I-IV) in a rat transverse slice preparation with attached dorsal roots. To study changes in synaptic inputs after neuroma formation, the sciatic nerve was sectioned and ligated 3 weeks before in vitro electrophysiological analysis. Horseradish peroxidase labeling of dorsal root axons indicated that Abeta fibers sprouted into laminae I-II from deeper laminae after sciatic nerve section. FP recordings from dorsal horns of normal spinal cord slices revealed long-latency synaptic responses in lamina II and short-latency responses in lamina III. The latencies of synaptic FPs recorded in lamina II of the dorsal horn after sciatic nerve section were reduced. The majority of monosynaptic EPSPs recorded with intracellular microelectrodes from lamina II neurons in control slices were elicited by high-threshold nerve stimulation, whereas the majority of monosynaptic EPSPs recorded in lamina III were elicited by low-threshold nerve stimulation. After sciatic nerve section, 31 of 57 (54%) EPSPs recorded in lamina II were elicited by low-threshold stimulation. The majority of low-threshold EPSPs in lamina II neurons after axotomy displayed properties similar to low-threshold EPSPs in lamina III of control slices. These results indicate that reoccupation of lamina II synapses by sprouting Abeta fibers normally terminating in lamina III occurs after sciatic nerve neuroma formation. Furthermore, these observations indicate that the lamina II neurons receive inappropriate sensory information from low-threshold mechanoreceptor after sciatic nerve neuroma formation. PMID:10662843

  11. Techniques of facial nerve block.

    PubMed Central

    Schimek, F; Fahle, M

    1995-01-01

    The efficacy of different techniques of facial nerve block for cataract surgery was investigated. Forty four patients underwent either modified O'Brien, Atkinson, van Lint, or lid blocks. Intentional muscle activity of the orbicularis oculi muscle was recorded and the area under the EMG curve calculated for quantitative comparison of muscle activity between the groups before and after injection of lignocaine with the vasoconstrictor naphazoline nitrate. In addition, the force of lid closure was measured and lid motility determined on a subjective score scale. Whereas the modified O'Brien and lid blocks nearly abolished the muscle activity recorded in the EMG (p < 0.003), the Atkinson and van Lint blocks did not significantly affect these variables. The O'Brien and lid blocks decreased the force of lid closure and lid movements far more effectively than the Atkinson and van Lint blocks (p < 0.0001). The topographic distribution of a mixture of metrizamide and lignocaine solutions was evaluated radiographically in eight additional patients, to assess potential causes for differences in the efficacy of the block techniques. The radiological results showed involvement of the region of the facial nerve trunk and its temporal and cervical divisions by the modified O'Brien block. The lid block, on the other hand, affected terminal branches of the facial nerve's temporal division. In this study, complete lid akinesia was achieved by both the modified O'Brien block and the lid block. However, because the modified O'Brien block involves the risk of neural injury to the facial nerve or its main divisions, the lid block is recommended as the most effective and safe method to achieve akinesia of the orbicularis oculi muscle. Images PMID:7696239

  12. Pleiotrophin and peripheral nerve injury

    Microsoft Academic Search

    Li Jin; Chen Jianghai; Liu Juan; Kang Hao

    2009-01-01

    The proto-oncogene pleiotrophin, discovered in 1989, was considered as a multifunctional growth factor, which played an important\\u000a role in tumor occurrence, development, and central nervous system. The latest research showed that pleiotrophin signal pathway\\u000a probably participated in neural repair after peripheral nerve injury, especially in the following critical points, such as\\u000a the protection of spinal cord neuron, the promotion of

  13. Plant root exudates

    Microsoft Academic Search

    Albert D. Rovira

    1969-01-01

    Conclusions  Although the quantities of organic compounds exuding from roots is not large, seldom exceeding 0.4% of the carbon photosynthesized,\\u000a they do exert a very strong influence on the soil microorganisms and may be significant in affecting plant nutrient availability.\\u000a There is evidence that exudates from the roots of some plants are toxic to roots of neighboring plants and to the

  14. Is Maxwell's Displacement Current a Current?

    ERIC Educational Resources Information Center

    French, A. P.

    2000-01-01

    Discusses in detail the claim that certain well-known physics experiments demonstrate the magnetic field produced by Maxwell's displacement current. Addresses the question of whether the displacement current acts as a source of magnetic field in the same way as a current in a wire would. (Contains 12 references.) (WRM)

  15. Displacement and Knowledge Construction in Literature Reviews.

    ERIC Educational Resources Information Center

    Steinley, Gary

    Two literature reviews are interpreted to demonstrate how they are informed by what the author labels the "displacement story," that is, a story of how one prevailing professional paradigm is replaced by another. This study demonstrates how the narration, structure, and language in each review render particular tellings of the displacement story.…

  16. Horizontal displacements of rock foundations of dams

    SciTech Connect

    Karlson, A.A.

    1987-08-01

    This paper uses geodetic survey methods to assess the horizontal displacements of dam foundations for several hydroelectric power plants in the Soviet Union. The effects of filling the reservoirs are outlined and the dependence of the degree of displacement on dam height is analyzed. The results are tabulated.

  17. Video Games, Adolescents, and the Displacement Effect

    ERIC Educational Resources Information Center

    Fisher, Carla Christine

    2012-01-01

    The displacement effect (the idea that time spent in one activity displaces time spent in other activities) was examined within the lens of adolescents' video game use and their time spent reading, doing homework, in physically active sports and activities, in creative play, and with parents and friends. Data were drawn from the Panel Study…

  18. BLOCK DISPLACEMENT METHOD FIELD DEMONSTRATION AND SPECIFICATIONS

    EPA Science Inventory

    The Block Displacement technique has been developed as a remedial action method for isolating large tracks of ground contaminated by hazardous waste. The technique places a low permeability barrier around and under a large block of contaminated earth. The Block Displacement proce...

  19. Displaced Homemakers: Vo-Tech Workshop Guide.

    ERIC Educational Resources Information Center

    Peltier, Wanda Jo

    Written for displaced homemaker programs in vocational-technical schools, this curriculum contains material designed so that instructors can prepare student manuals appropriate to almost any educational support situation for displaced homemakers. An overview provides information on special needs groups, curriculum use, and resources and sample…

  20. Using a 2D displacement sensor to derive 3D displacement information

    NASA Technical Reports Server (NTRS)

    Soares, Schubert F. (Inventor)

    2002-01-01

    A 2D displacement sensor is used to measure displacement in three dimensions. For example, the sensor can be used in conjunction with a pulse-modulated or frequency-modulated laser beam to measure displacement caused by deformation of an antenna on which the sensor is mounted.

  1. Controlled Field and Laboratory Experiments to Investigate soil-root Interactions and Streambank Stability.

    NASA Astrophysics Data System (ADS)

    Pollen, N. L.; Simon, A.

    2002-12-01

    Riparian vegetation has a number of mechanical and hydrologic effects on streambank stability, some of which are positive and some of which are negative. The mechanical reinforcement provided by root networks is one of the most important stabilizing factors, as roots are strong in tension but weak in compression and conversely soil is strong in compression but weak in tension. A soil that contains roots therefore has increased shear strength due to the production of a reinforced matrix, which is stronger than the soil or roots separately (Thorne, 1990). Quantification and understanding of the way the soil and roots interact individually and as a complete matrix is important if we are to predict the reinforcing effects of different types of riparian vegetation in streambank stabilizing schemes. Previous estimates of the contribution of root networks to soil strength have been attained either by using equations that sum root tensile and the soil shear strengths (eg. Wu et al., 1979), or by carrying out shear tests of root-permeated soils. However, neither of these methods alone allows a full investigation and understanding of the interactions that take place between the soil and the roots as a soil is sheared. These interactions are complex, and the simple addition of root tensile and soil shear strengths may therefore lead to overestimation of the increased strength provided to the soil by the roots, as the rate of mobilization of stress in the roots may not be the same as that of the soil (Waldron and Dakessian, 1981; Pollen et al., 2002). This paper describes a series of experiments that were carried out to test the material properties of roots, and soil samples from a streambank along Goodwin Creek, N. Mississippi. Results from field experiments carried out to measure root-tensile strengths, and stress-displacement characteristics of roots, were compared with laboratory shear tests of soil samples from Goodwin Creek. It was shown that the roots of different species took up strain at different rates, and that these rates differed considerably from that of the Goodwin Creek soil sample. For example, the mean displacement of Eastern Sycamore roots before breaking was 3.57cm, whereas the displacement of the soil sample at peak strength was just 0.68cm, suggesting that the critical factor in root reinforcement of soil matrices may in fact be the rate of mobilization of tension in the roots, rather than their ultimate tensile strength. Isolation and testing of the roots and soil separately, in the field and the laboratory, allowed the formulation of two hypotheses to explain the way in which roots and soil interact during shearing: As the soil shears, either the roots reinforce the soil after the peak soil strength has been overcome, until the ultimate tensile strength of the roots is reached, or the roots only reinforce the soil until the peak soil strength has been reached, beyond which point the entire root-soil matrix fails. These hypotheses were then tested by running a series of laboratory-shear tests of root-permeated and non-root-permeated soils. The results of these studies were used in the ARS-Bank Stability Model (ver. 2.0) to simulate the increase in factor of safety of streambanks due to root reinforcement. The calculations suggest that overestimation of increased soil shear strength from the root network using the sum of root tensile and soil shear strengths, may be as high as 78% for Eastern Sycamore roots which uptake strain slowly, but only 10% for Sandbar Willow roots, which take up tension more quickly.

  2. Use of nerve elongator to repair short-distance peripheral nerve defects: a prospective randomized study

    PubMed Central

    Bai, Lu; Wang, Tian-bing; Wang, Xin; Zhang, Wei-wen; Xu, Ji-hai; Cai, Xiao-ming; Zhou, Dan-ya; Cai, Li-bing; Pan, Jia-dong; Tian, Min-tao; Chen, Hong; Zhang, Dian-ying; Fu, Zhong-guo; Zhang, Pei-xun; Jiang, Bao-guo

    2015-01-01

    Repair techniques for short-distance peripheral nerve defects, including adjacent joint flexion to reduce the distance between the nerve stump defects, “nerve splint” suturing, and nerve sleeve connection, have some disadvantages. Therefore, we designed a repair technique involving intraoperative tension-free application of a nerve elongator and obtained good outcomes in the repair of short-distance peripheral nerve defects in a previous animal study. The present study compared the clinical outcomes between the use of this nerve elongator and performance of the conventional method in the repair of short-distance transection injuries in human elbows. The 3-, 6-, and 12-month postoperative follow-up results demonstrated that early neurological function recovery was better in the nerve elongation group than in the conventional group, but no significant difference in long-term neurological function recovery was detected between the two groups. In the nerve elongation group, the nerves were sutured without tension, and the duration of postoperative immobilization of the elbow was decreased. Elbow function rehabilitation was significantly better in the nerve elongation group than in the control group. Moreover, there were no security risks. The results of this study confirm that the use of this nerve elongator for repair of short-distance peripheral nerve defects is safe and effective.

  3. Secondary digital nerve repair in the foot with resorbable p(DLLA-epsilon-CL) nerve conduits.

    PubMed

    Meek, Marcel F; Nicolai, Jean-Philippe A; Robinson, Peter H

    2006-04-01

    Nerve guides are increasingly being used in peripheral nerve repair. In the last decade, much preclinical research has been undertaken into a resorbable nerve guide composed of p(DLLA-epsilon-CL). This report describes the results of secondary digital nerve reconstruction in the foot in a patient with post-traumatic neuromas of the common plantar digital nerves II-III and III-IV. The neuromas were resected and reconstruction of the nerves was carried out with resorbable Neurolac nerve guides. The Pressure Specified Sensory Device was used to measure the static (s) and moving (m) 1- and 2-point discrimination (PD). Fourteen months after nerve repair, the m1-PD returned in all digital nerves. The s1-PD returned only on the lateral side of the second toe. The m2-PD and s2-PD did not return in any of the toes originally innervated by the reconstructed nerves. According to the British Classification System, the sensory nerve recovery was poor. However, there were no complaints of painful neuromas after this procedure. In conclusion, this report shows no beneficial effects of Neurolac nerve guides in terms of return of sensibility after repair of common plantar digital nerves. Painful neuromas, however, could be well-treated. PMID:16780042

  4. [Anatomical variants of the medial calcaneal nerve and the Baxter nerve in the tarsal tunnel].

    PubMed

    Martín-Oliva, X; Elgueta-Grillo, J; Veliz-Ayta, P; Orosco-Villaseñor, S; Elgueta-Grillo, M; Viladot-Perice, R

    2013-01-01

    The tarsal tunnel is composed of the posterior border of the medial malleoulus, the posterior aspect of the talus and the medial aspect of the calcaneus. The medial calcaneal nerve emerges from the posterior aspect of the posterior tibial nerve in 75% of cases and from the lateral plantar nerve in the remaining 25%. Finally, the medial calcaneal nerve ends as a single terminal branch in 79% of cases and in numerous terminal branches in the remaining 21%. To describe the anatomical variants of the posterior tibial nerve and its terminal branches. To describe the steps for tarsal tunnel release. To describe Baxter nerve release. The anatomical variants of the posterior tibial nerve and its terminal branches within the tarsal tunnel were studied. Then the Lam technique was performed; it consists of: 1) opening of the laciniate ligament, 2) opening of the fascia over the abductor hallucis muscle, 3) exoneurolysis of the posterior tibial nerve and its terminal branches, identifying the emergence and pathway of the medial calcaneal branch, the lateral plantar nerve and its Baxter nerve branch and the medial plantar nerve. Baxter nerve was found in 100% of cases. In 100% of cases in our series the nerve going to the abductor digiti minimi muscle of the foot was found; 87.5% of cases had two terminal branches. The dissections proved that a crucial step was the release of the distal tarsal tunnel. PMID:24701749

  5. Imunoreactivity of zinc transporter 7 (ZNT7) in mouse dorsal root ganglia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the present study, we showed for the first time the localization of ZNT7 immunoreactivity in the mouse dorsal root ganglion (DRG) by means of immunohistochemistry and confocal laser scanning microscopy. Our results revealed that ZNT7 immunoreactivity was abundantly expressed in the nerve cells of...

  6. A quantitative immunohistochemical study of the endoneurium in the rat dorsal and ventral spinal roots

    Microsoft Academic Search

    Petr Dubovy ´; Ilona Klusáková; Ivana Svíženská

    2002-01-01

    The dorsal and ventral spinal roots contain different types of axons. The endoneurial extracellular matrix (ECM) among them is produced by Schwann cells and fibroblasts under the control of the axons. Chondroitin sulfate proteoglycan, fibronectin, tenascin-C, and thrombospondin are common components of the endoneurial ECM involved in the normal function as well as regeneration of the peripheral nerve. The present

  7. Surgical treatment of paresthesia following over-extension of root canal filling material: a case report.

    PubMed

    Gumru, O Z; Yalcin, S

    1991-03-01

    A case of paresthesia of the mental nerve following over-extension of root canal filling material into the inferior alveolar canal is presented. The causes of this complication are discussed and the importance of performing surgical treatment as early as possible is emphasized. PMID:2051218

  8. [Endoscopically assisted nerve decompression of nerve nerve compression syndromes at the upper extremity].

    PubMed

    Bignion, Dietmar; Leclère, Franck Marie P; Vögelin, Esther

    2014-07-01

    Besides carpal tunnel and cubital tunnel syndrome, other nerve compression or constriction syndromes exist at the upper extremity. Using the technique of endoscopically assisted decompression such rare nerve compression syndromes of the upper extremity can be treated. The technique of endoscopical decompression is presented in six patients with rare compression or hour-glass-like constriction syndromes at the upper extremity. According to the classification of Roles and Maudsley in 5 of 6 cases excellent results were recorded. All but one patient considered the results excellent. The poorest responder developed a CRPS II and refused postoperative physiotherapy. Endoscopically assisted decompression in rare compression syndrome of the upper extremity is highly appreciated by patients and provides excellent functional results. PMID:24972520

  9. Interest of Electrostimulation of Peripheral Motor Nerves during Percutaneous Thermal Ablation

    SciTech Connect

    Tsoumakidou, Georgia, E-mail: gtsoumakidou@yahoo.com; Garnon, Julien, E-mail: juliengarnon@gmail.com; Ramamurthy, Nitin, E-mail: nitin_ramamurthy@hotmail.com; Buy, Xavier, E-mail: xbuy@ymail.com; Gangi, Afshin, E-mail: gangi@unistra.fr [University Hospital of Strasbourg (France)] [University Hospital of Strasbourg (France)

    2013-12-15

    Purpose: We present our experience of utilizing peripheral nerve electrostimulation as a complementary monitoring technique during percutaneous thermal ablation procedures; and we highlight its utility and feasibility in the prevention of iatrogenic neurologic thermal injury. Methods: Peripheral motor nerve electrostimulation was performed in 12 patients undergoing percutaneous image-guided thermal ablations of spinal/pelvic lesions in close proximity to the spinal cord and nerve roots. Electrostimulation was used in addition to existing insulation (active warming/cooling with hydrodissection, passive insulation with CO{sub 2} insufflation) and temperature monitoring (thermocouples) techniques. Impending neurologic deficit was defined as a visual reduction of muscle response or need for a stronger electric current to evoke muscle contraction, compared with baseline. Results: Significant reduction of the muscle response to electrostimulation was observed in three patients during the ablation, necessitating temporary interruption, followed by injection of warm/cool saline. This resulted in complete recovery of the muscle response in two cases, while for the third patient the response did not improve and the procedure was terminated. No patient experienced postoperative motor deficit. Conclusion: Peripheral motor nerve electrostimulation is a simple, easily accessible technique allowing early detection of impending neurologic injury during percutaneous image-guided thermal ablation. It complements existing monitoring techniques and provides a functional assessment along the whole length of the nerve.

  10. Spontaneous intraneural hematoma of the sural nerve.

    PubMed

    Richardson, Shawn S; McLawhorn, Alexander S; Mintz, Douglas N; DiCarlo, Edward F; Weiland, Andrew J

    2015-04-01

    Symptomatic intraneural hemorrhage occurs rarely. It presents with pain and/or weakness in the distribution following the anatomic innervation pattern of the involved nerve. When a purely sensory nerve is affected, the symptoms can be subtle. We present a previously healthy 36-year-old female who developed an atraumatic, spontaneous intraneural hematoma of her sural nerve. Sural dysfunction was elicited from the patient's history and physical examination. The diagnosis was confirmed with magnetic resonance imaging, and surgical decompression provided successful resolution of her preoperative symptoms. To our knowledge, this entity has not been reported previously. Our case highlights the importance of having a high index of suspicion for nerve injury or compression in patients whose complaints follow a typical peripheral nerve distribution. Prior studies have shown that the formation of intraneural hematoma and associated compression of nerve fibers result in axonal degeneration, and surgical decompression decreases axonal degeneration and aids functional recovery. PMID:25311865

  11. Imaging the Facial Nerve: A Contemporary Review

    PubMed Central

    Gupta, Sachin; Mends, Francine; Hagiwara, Mari; Fatterpekar, Girish; Roehm, Pamela C.

    2013-01-01

    Imaging plays a critical role in the evaluation of a number of facial nerve disorders. The facial nerve has a complex anatomical course; thus, a thorough understanding of the course of the facial nerve is essential to localize the sites of pathology. Facial nerve dysfunction can occur from a variety of causes, which can often be identified on imaging. Computed tomography and magnetic resonance imaging are helpful for identifying bony facial canal and soft tissue abnormalities, respectively. Ultrasound of the facial nerve has been used to predict functional outcomes in patients with Bell's palsy. More recently, diffusion tensor tractography has appeared as a new modality which allows three-dimensional display of facial nerve fibers. PMID:23766904

  12. Entrapment neuropathy of the ulnar nerve.

    PubMed

    Elhassan, Bassem; Steinmann, Scott P

    2007-11-01

    Ulnar nerve entrapment is the second most common nerve entrapment syndrome of the upper extremity. Although it may occur at any location along the length of the nerve, it is most common in the cubital tunnel. Ulnar nerve entrapment produces numbness in the ring and little fingers and weakness of the intrinsic muscles in the hand. Patient presentation and symptoms vary according to the site of entrapment. Treatment options are often determined by the site of pathology. Many patients benefit from nonsurgical treatment (eg, physical therapy, bracing, injection). When these methods fail or when sensory or motor impairment progresses, surgical release of the nerve at the site of entrapment should be considered. Surgical release may be done alone or with nerve transposition at the elbow. Most patients report symptomatic relief following surgery. PMID:17989418

  13. [Nerve and vascular entrapment in athletes].

    PubMed

    Pessis, E; Drapé, J L; Guérini, H; Bach, F; Feydy, A; Chevrot, A

    2007-01-01

    Peripheral nerve entrapment syndromes involve the compression of a short segment of a nerve at a specific site, as a result of the vulnerability of that nerve as it passes through a fibroosseous tunnel or an opening in fibrous or muscular tissue. Injury of the nerve may occur as a result of compression by the overlying structures. Another mechanism of injury is traction of the nerve, with or without friction of the nerve, as it travels and sharply changes direction around critical points. Imaging can be particularly helpful for the diagnosis of these uncommon injuries. Percutaneous decompression of a ganglion cyst or perineural injection for therapeutic purposes with the aid of fluoroscopy, CT, or ultrasound guidance can be performed in specific areas. PMID:17299357

  14. Lentiviral vectors enveloped with rabies virus glycoprotein can be used as a novel retrograde tracer to assess nerve recovery in rat sciatic nerve injury models.

    PubMed

    Wei, Yujun; Gong, Kai; Ao, Qiang; Wang, Aijun; Gong, Yandao; Zuo, Huancong; Zhang, Yuqi; Wang, James; Wang, Guihuai

    2014-02-01

    Retrograde labeling has become the new "gold standard" technique to evaluate the recovery of injured peripheral nerves. In this study, lentiviral vectors with rabies virus glycoprotein envelop (RABV-G-LV) and RFP genes are injected into gastrocnemius muscle to determine the location of RFP in sciatic nerves. We then examine RFP expression in the L4-S1 spinal cord and sensory dorsal root ganglia and in the rat sciatic nerve, isolated Schwann cells, viral dose to expression relationship and the use of RABV-G-LV as a retrograde tracer for regeneration in the injured rat sciatic nerve. VSV-G-LV was used as control for viral envelope specificity. Results showed that RFP were positive in the myelin sheath and lumbar spinal motorneurons of the RABV-G-LV group. RFP gene could be detected both in myelinated Schwann cells and lumbar spinal motor neurons in the RABV-G-LV group. Schwann cells isolated from the RABV-G-LV injected postnatal Sprague Dawley rats were also RFP-gene positive. All the results obtained in the VSV-G-LV group were negative. Distribution of RFP was unaltered and the level of RFP expression increasing with time progressing. RABV-G-LV could assess the amount of functional regenerating nerve fibers two months post-operation in the four models. This method offers an easy-operated and consistent standardized approach for retrograde labeling regenerating peripheral nerves, which may be a significant supplement for the previous RABV-G-LV-related retrograde labeling study. PMID:24326614

  15. Centrifugal nerve fibers in the adult human optic nerve: 16 days after enucleation.

    PubMed Central

    Wolter, J R

    1978-01-01

    The optic nerve stump of a 56-year-old patient was removed 16 days after enucleation of the corresponding eyeball. The stumps of numerous centrifugal (efferent) nerve fibers are demonstrated histologically in this optic nerve central to the 16-day old surgical cut. Electron-microscopic views of the centrifugal nerve fibers are offered for the first time. The findings are further evidence for the existence of centrifugal fibers in the human optic nerve. The nerve fiber stumps exhibit reactive terminal swellings pointing towards the surgical cut indicating axoplasmic flow in that direction. It is of special interest that the centrifugal nerve fibers of this 56-year-old patient lack any evidence of attempted regeneration that has been observed under similar conditions in th optic nerve stump of a child. Images FIGURE 3 A FIGURE 3 B FIGURE 3 C FIGURE 3 D FIGURE 1 FIGURE 2 FIGURE 4 FIGURE 5 FIGURE 6 FIGURE 7 PMID:754369

  16. Spinal root and plexus hypertrophy in chronic inflammatory demyelinating polyneuropathy.

    PubMed

    Duggins, A J; McLeod, J G; Pollard, J D; Davies, L; Yang, F; Thompson, E O; Soper, J R

    1999-07-01

    MRI was performed on the spinal roots, brachial and lumbar plexuses of 14 patients with chronic inflammatory demyelinating polyneuropathy (CIDP). Hypertrophy of cervical roots and brachial plexus was demonstrated in eight cases, six of whom also had hypertrophy of the lumbar plexus. Of 11 patients who received gadolinium, five of six cases with hypertrophy and one of five without hypertrophy demonstrated enhancement. All patients with hypertrophy had a relapsing-remitting course and a significantly longer disease duration. Gross onion-bulb formations were seen in a biopsy of nerve from the brachial plexus in one case with clinically evident nodular hypertrophy. We conclude that spinal root and plexus hypertrophy may be seen on MRI, particularly in cases of CIDP of long duration, and gadolinium enhancement may be present in active disease. PMID:10388803

  17. Perineal nerve stimulation for urinary sphincter control

    Microsoft Academic Search

    A. Shafik

    1994-01-01

    The effect of electrostimulation of the perineal nerve on the external urethral sphincter (EUS) and urethral pressure was studied in 9 dogs. The nerve was displayed in the ischiorectal fossa through a para-anal incision and an electrode was applied to it. Perineal nerve stimulation effected an increase of the urethral pressure (PPP>0.05). The greater the stimulus frequency, the higher the

  18. Disorders of Cranial Nerves IX and X

    PubMed Central

    Erman, Audrey B.; Kejner, Alexandra E.; Hogikyan, Norman D.; Feldman, Eva L.

    2014-01-01

    The glossopharyngeal and vagus nerves mediate the complex interplay between the many functions of the upper aerodigestive tract. Defects may occur anywhere from the brainstem to the peripheral nerve and can result in significant impairment in speech, swallowing, and breathing. Multiple etiologies can produce symptoms. This review will broadly examine the normal functions, clinical examination, and various pathologies of cranial nerves IX and X. PMID:19214937

  19. Clinical utility of peripheral nerve biopsy

    Microsoft Academic Search

    David Lacomis

    2005-01-01

    Histopathologic evaluation of nerve biopsy specimens provides important diagnostic information in some patients with peripheral\\u000a neuropathy. The role of nerve biopsy is more restricted than that of muscle biopsy. Nerve biopsy is utilized mainly for diagnosis\\u000a of vasculitis and infiltrative neuropathies. It is also utilized in diagnosis of atypical inflammatory demyelinating neuropathies\\u000a in which the clinical, electrodiagnostic, and laboratory features

  20. ROOT Statistical Software

    E-print Network

    Moneta, Lorenzo; Brun, R; Kreshuk, Anna

    2008-01-01

    Advanced mathematical and statistical computational methods are required by the LHC experiments for analyzing their data. Some of these methods are provided by the ROOT project, a C++ Object Oriented framework for large scale data handling applications. We review the current mathematical and statistical classes present in ROOT, emphasizing the recent developments.

  1. Irrational Square Roots

    ERIC Educational Resources Information Center

    Misiurewicz, Michal

    2013-01-01

    If students are presented the standard proof of irrationality of [square root]2, can they generalize it to a proof of the irrationality of "[square root]p", "p" a prime if, instead of considering divisibility by "p", they cling to the notions of even and odd used in the standard proof?

  2. Seeds: Roots and Shoots

    NSDL National Science Digital Library

    Education Development Center, Inc.

    2010-01-01

    In this indepth hands-on activity, learners build a structure that allows them to observe the growth of roots and the correlation between root growth and stem extension. Because no dirt is used in this arrangement, a guiding question can be posed: What does the plant need to grow? The PDF includes activity rationale, procedure, background and follow-up discussion suggestions.

  3. ROOTING GUATEMALAN AVOCADO CUTTINGS

    Microsoft Academic Search

    E. F. Frolich

    SUMMARY A method is described which, although not considered commercially practical, proved to be very successful in rooting cuttings of Guatemalan avocado varieties. Essentially it consists of obtaining cuttings from stems, the bases of which have at no time been exposed to light or low humidity. In certain experimental work with the avocado, own rooted trees, that is trees propagated

  4. Development and Evolution of Character Displacement

    PubMed Central

    Pfennig, David W.; Pfennig, Karin S.

    2012-01-01

    Character displacement occurs when competition for either resources or successful reproduction imposes divergent selection on interacting species, causing divergence in traits associated with resource use or reproduction. Here, we describe how character displacement can be mediated either by genetically canalized changes (i.e., changes that reflect allelic or genotype frequency changes) or by phenotypic plasticity. We also discuss how these two mechanisms influence the tempo of character displacement. Specifically, we suggest that, under some conditions, character displacement mediated by phenotypic plasticity might occur more rapidly than that mediated by genetically canalized changes. Finally, we describe how these two mechanisms may act together and determine character displacement’s mode, such that it proceeds through an initial phase in which trait divergence is environmentally induced to a later phase in which divergence becomes genetically canalized. This plasticity-first hypothesis predicts that character displacement should be generally mediated by ancestral plasticity and that it will arise similarly in multiple, independently evolving populations. We conclude by highlighting future directions for research that would test these predictions. PMID:22257002

  5. Endoscopic ulnar nerve release and transposition.

    PubMed

    Morse, Levi P; McGuire, Duncan T; Bain, Gregory I

    2014-03-01

    The most common site of ulnar nerve compression is within the cubital tunnel. Surgery has historically involved an open cubital tunnel release with or without transposition of the nerve. A comparative study has demonstrated that endoscopic decompression is as effective as open decompression and has the advantages of being less invasive, utilizing a smaller incision, producing less local symptoms, causing less vascular insult to the nerve, and resulting in faster recovery for the patient. Ulnar nerve transposition is indicated with symptomatic ulnar nerve instability or if the ulnar nerve is located in a "hostile bed" (eg, osteophytes, scarring, ganglions, etc.). Transposition has previously been performed as an open procedure. The authors describe a technique of endoscopic ulnar nerve release and transposition. Extra portals are used to allow retractors to be inserted, the medial intermuscular septum to be excised, cautery to be used, and a tape to control the position of the nerve. In our experience this minimally invasive technique provides good early outcomes. This report details the indications, contraindications, surgical technique, and rehabilitation of the endoscopic ulnar nerve release and transposition. PMID:24296546

  6. Tissue engineered constructs for peripheral nerve surgery

    PubMed Central

    Johnson, P. J.; Wood, M. D.; Moore, A. M.; Mackinnon, S. E.

    2013-01-01

    Summary Background Tissue engineering has been defined as “an interdisciplinary field that applies the principles of engineering and life sciences toward the development of biological substitutes that restore, maintain, or improve tissue function or a whole organ”. Traumatic peripheral nerve injury resulting in significant tissue loss at the zone of injury necessitates the need for a bridge or scaffold for regenerating axons from the proximal stump to reach the distal stump. Methods A review of the literature was used to provide information on the components necessary for the development of a tissue engineered peripheral nerve substitute. Then, a comprehensive review of the literature is presented composed of the studies devoted to this goal. Results Extensive research has been directed toward the development of a tissue engineered peripheral nerve substitute to act as a bridge for regenerating axons from the proximal nerve stump seeking the distal nerve. Ideally this nerve substitute would consist of a scaffold component that mimics the extracellular matrix of the peripheral nerve and a cellular component that serves to stimulate and support regenerating peripheral nerve axons. Conclusions The field of tissue engineering should consider its challenge to not only meet the autograft “gold standard” but also to understand what drives and inhibits nerve regeneration in order to surpass the results of an autograft. PMID:24385980

  7. Dural ectasia of the optic nerve sheath.

    PubMed

    Kacem, Hanane Hadj; Hammani, Lehcen; Ajana, Ali; Nassar, Itimad

    2014-01-01

    Optic nerve dural ectasia is a rare cause of optic nerve sheath enlargement due to the accumulation of CSF around the optic nerve with no associated pathology. It diagnosed by MRI studies and can follow benign or sometimes an unfavorable course. We describe the case of a 24-day-old female referred for a visual blurring, which we diagnosed as a dural ectasia of the optic nerve sheath by MRI and confirmed in surgical intervention. We present this case report to illustrate the classic imaging features of the disease. PMID:25374645

  8. Dural ectasia of the optic nerve sheath

    PubMed Central

    Kacem, Hanane Hadj; Hammani, Lehcen; Ajana, Ali; Nassar, Itimad

    2014-01-01

    Optic nerve dural ectasia is a rare cause of optic nerve sheath enlargement due to the accumulation of CSF around the optic nerve with no associated pathology. It diagnosed by MRI studies and can follow benign or sometimes an unfavorable course. We describe the case of a 24-day-old female referred for a visual blurring, which we diagnosed as a dural ectasia of the optic nerve sheath by MRI and confirmed in surgical intervention. We present this case report to illustrate the classic imaging features of the disease. PMID:25374645

  9. One-stage human acellular nerve allograft reconstruction for digital nerve defects

    PubMed Central

    Li, Xue-yuan; Hu, Hao-liang; Fei, Jian-rong; Wang, Xin; Wang, Tian-bing; Zhang, Pei-xun; Chen, Hong

    2015-01-01

    Human acellular nerve allografts have a wide range of donor origin and can effectively avoid nerve injury in the donor area. Very little is known about one-stage reconstruction of digital nerve defects. The present study observed the feasibility and effectiveness of human acellular nerve allograft in the reconstruction of < 5-cm digital nerve defects within 6 hours after injury. A total of 15 cases of nerve injury, combined with nerve defects in 18 digits from the Department of Emergency were enrolled in this study. After debridement, digital nerves were reconstructed using human acellular nerve allografts. The patients were followed up for 6–24 months after reconstruction. Mackinnon-Dellon static two-point discrimination results showed excellent and good rates of 89%. Semmes-Weinstein monofilament test demonstrated that light touch was normal, with an obvious improvement rate of 78%. These findings confirmed that human acellular nerve allograft for one-stage reconstruction of digital nerve defect after hand injury is feasible, which provides a novel trend for peripheral nerve reconstruction. PMID:25788927

  10. A simple model of radial nerve injury in the rhesus monkey to evaluate peripheral nerve repair

    PubMed Central

    Wang, Dong; Huang, Xijun; Fu, Guo; Gu, Liqiang; Liu, Xiaolin; Wang, Honggang; Hu, Jun; Yi, Jianhua; Niu, Xiaofeng; Zhu, Qingtang

    2014-01-01

    Current research on bone marrow stem cell transplantation and autologous or xenogenic nerve transplantation for peripheral nerve regeneration has mainly focused on the repair of peripheral nerve defects in rodents. In this study, we established a standardized experimental model of radial nerve defects in primates and evaluated the effect of repair on peripheral nerve injury. We repaired 2.5-cm lesions in the radial nerve of rhesus monkeys by transplantation of autografts, acellular allografts, or acellular allografts seeded with autologous bone marrow stem cells. Five months after surgery, regenerated nerve tissue was assessed for function, electrophysiology, and histomorphometry. Postoperative functional recovery was evaluated by the wrist-extension test. Compared with the simple autografts, the acellular allografts and allografts seeded with bone marrow stem cells facilitated remarkable recovery of the wrist-extension functions in the rhesus monkeys. This functional improvement was coupled with radial nerve distal axon growth, a higher percentage of neuron survival, increased nerve fiber density and diameter, increased myelin sheath thickness, and increased nerve conduction velocities and peak amplitudes of compound motor action potentials. Furthermore, the quality of nerve regeneration in the bone marrow stem cells-laden allografts group was comparable to that achieved with autografts. The wrist-extension test is a simple behavioral method for objective quantification of peripheral nerve regeneration. PMID:25206757

  11. The Cranial Nerve Skywalk: A 3D Tutorial of Cranial Nerves in a Virtual Platform

    ERIC Educational Resources Information Center

    Richardson-Hatcher, April; Hazzard, Matthew; Ramirez-Yanez, German

    2014-01-01

    Visualization of the complex courses of the cranial nerves by students in the health-related professions is challenging through either diagrams in books or plastic models in the gross laboratory. Furthermore, dissection of the cranial nerves in the gross laboratory is an extremely meticulous task. Teaching and learning the cranial nerve pathways…

  12. Ginsenoside Rg1 promotes peripheral nerve regeneration in rat model of nerve crush injury

    Microsoft Academic Search

    Junxiong Ma; Wenxian Li; Ruifeng Tian; Wei Lei

    2010-01-01

    Searching for effective drugs which are capable of promoting nerve regeneration after nerve injuries has gained extensive attention. Ginsenoside Rg1 (GRg1) is one of the bioactive compounds extracted from ginseng. GRg1 has been shown to be neuroprotective in many in vitro studies, which raises the possibility of using GRg1 as a neuroprotective agent after nerve injuries. However, such a possibility

  13. Laryngeal Paralysis: Distinguishing Xth Nerve from Recurrent Nerve Paralysis Through Videoendoscopic Swallowing Study (VESS)

    Microsoft Academic Search

    Sophie Perie ´; Bernard Roubeau; Jean Lacau St. Guily

    2003-01-01

    Distinction between unilateral recurrent laryngeal nerve paralysis and Xth nerve paralysis is a rarely addressed issue in the literature. However, it may be crucial to examine the cause of the paralysis and to perform the appropriate investigation. The videoendoscopic swallowing study has been demonstrated to be a useful tool in assessing pharyngeal function. Since in unilateral Xth nerve paralysis the

  14. Characterization of neuronal death and functional deficits following nerve injury during the early postnatal developmental period in rats.

    PubMed

    Kemp, Stephen W P; Chiang, Cameron D; Liu, Edward H; Wood, Matthew D; Willand, Michael P; Gordon, Tessa; Borschel, Gregory H

    2015-01-01

    In contrast to adult rat nerve injury models, neonatal sciatic nerve crush leads to massive motor and sensory neuron death. Death of these neurons results from both the loss of functional contact between the nerve terminals and their targets, and the inability of immature Schwann cells in the distal stump of the injured nerve to sustain regeneration. However, current dogma holds that little to no motoneuron death occurs in response to nerve crush at postnatal day 5 (P5). The purpose of the current study was to fully characterize the extent of motor and sensory neuronal death and functional recovery following sciatic nerve crush at mid-thigh level in rats at postnatal days 3-30 (P3-P30), and then compare this to adult injured animals. Following nerve crush at P3, motoneuron numbers were reduced to 35% of that of naïve uninjured animals. Animals in the P5 and P7 group also displayed statistically fewer motoneurons than naïve animals. Animals that were injured at P30 or earlier displayed statistically lower sensory neuron counts in the dorsal root ganglion than naïve controls. Surprisingly, complete behavioral recovery was observed exclusively in the P30 and adult injured groups. Similar results were observed in muscle twitch/tetanic force analysis, motor unit number estimation and wet muscle weights. Rats in both the P5 and P7 injury groups displayed significant neuronal death and impaired functional recovery following injury, challenging current dogma and suggesting that severe deficits persist following nerve injury during this early postnatal developmental period. These findings have important implications concerning the timing of neonatal nerve injury in rats. PMID:25592862

  15. An inconvenient truth: treatment of displaced paediatric supracondylar humeral fractures.

    PubMed

    Donnelly, M; Green, C; Kelly, I P

    2012-06-01

    The need for emergent management of displaced paediatric supracondylar humeral fractures is being questioned in the literature. Open reduction rates of up to 46% have been reported in the non-emergent management of these injuries. At our institution these fractures are managed as operative emergencies by senior personnel. To examine the ongoing need for this policy we reviewed our results. All patients managed over a five year period with Gartland type IIB or III paeditric supracondylar humeral fractures were identified and a comprehensive chart and radiographic review undertaken. The mean time from injury to fracture reduction and stabilization was 6.6 h. Consultants performed or supervised 90% of cases. Open reduction was necessary in 5% of cases. Complications included a perioperative nerve injury rate of 6% and a superficial pin site infection rate of 3%. This study suggests that, despite the challenge to trauma on-call rostering, the emergency management of these injuries is advantageous to patients in units of our size. Based on the data presented here we continue our practice of emergent management. We suggest that units of a similar size to our own would show a benefit from an analogous policy albeit an inconvenient truth. PMID:22525415

  16. Palsies of Cranial Nerves That Control Eye Movement

    MedlinePLUS

    ... Disorders 4 Palsies of Cranial Nerves That Control Eye Movement These disorders involve paralysis of one of the cranial nerves that control eye movement (the 3rd, 4th, or 6th nerve), impairing the ...

  17. Nerve repair by means of tubulization: past, present, future.

    PubMed

    Konofaos, P; Ver Halen, J P

    2013-03-01

    Peripheral nerve injury may result in injury without gaps or injury with gaps between nerve stumps. In the presence of a nerve defect, the placement of an autologous nerve graft is the current gold standard for nerve restoration. The clinical employment of tubes as an alternative to autogenous nerve grafts is mainly justified by the limited availability of donor tissue for nerve autografts and their related morbidity. The purpose of this review is to present an overview of the literature on the applications of nerve conduits in peripheral nerve repair. Moreover, the different steps that are involved in the design of an ideal nerve conduit for peripheral nerve repair, including the choice of biomaterial, fabrication technique, and the various potential modifications to the common hollow nerve tube, are also discussed. PMID:23303520

  18. Detergent-free Decellularized Nerve Grafts for Long-gap Peripheral Nerve Reconstruction

    PubMed Central

    Vasudevan, Srikanth; Huang, Jiying; Botterman, Barry; Matloub, Hani S.; Keefer, Edward

    2014-01-01

    Background: Long-gap peripheral nerve defects arising from tumor, trauma, or birth-related injuries requiring nerve reconstruction are currently treated using nerve autografts and nerve allografts. Autografts are associated with limited supply and donor-site morbidity. Allografts require administration of transient immunosuppressants, which has substantial associated risks. To overcome these limitations, we investigated the use of detergent-free decellularized nerve grafts to reconstruct long-gap nerve defects in a rodent model and compared it with existing detergent processing techniques. Methods: Nerve grafts were harvested from the sciatic nerves of 9 donor rats. Twenty-four recipient rats were divided into 4 groups (6 animals per group): (1) nerve grafts (NG, positive control), (2) detergent-free decellularized (DFD) grafts, (3) detergent decellularized grafts, and (4) silicone tube conduits (negative control). Each recipient rat had a 3.5-cm graft or conduit sutured across a sciatic nerve transection injury. All animals were harvested at 12 weeks postimplantation for functional muscle analysis and nerve histomorphometry. Results: Histomorphometry results indicated maximum growth in NG when compared with other groups. DFD and detergent decellularized groups showed comparable regeneration at 12 weeks. Silicone tube group showed no regeneration as expected. Muscle force data indicated functional recovery in NG and DFD groups only. Conclusions: This study describes a detergent-free nerve decellularization technique for reconstruction of long-gap nerve injuries. We compared DFD grafts with an established detergent processing technique and found that DFD nerve grafts are successful in promoting regeneration across long-gap peripheral nerve defects as an alternative to existing strategies. PMID:25426384

  19. Theory of multicomponent gas/oil displacements

    SciTech Connect

    Orr, F.M. Jr.; Dindoruk, B.; Johns, R.T. [Stanford Univ., CA (United States). Dept. of Petroleum Engineering

    1995-08-01

    Chromatographic separations that occur during two-phase flow in a porous medium are analyzed for one-dimensional, dispersion-free displacement of a liquid hydrocarbon mixture (oil) by a vapor phase mixture (gas). The authors show that displacement behavior is controlled by a set of key equilibrium the lines, all of which are determined by geometric constructions in composition space: two of the key tie lines are those that extend through the initial oil and injection gas compositions, and the remainder are tie lines that are located at intersections of ruled surfaces of tie lines. Very efficient displacement of oil by gas results if any of the key tie lines is a critical tie line. That high displacement efficiency is the basis of so-called miscible gas injection processes for enhanced oil recovery.

  20. Micrograting Displacement Sensor with Integrated Electrostatic Actuation

    NASA Astrophysics Data System (ADS)

    Yao, Bao-Yin; Feng, Li-Shuang; Wang, Xiao; Liu, Wei-Fang; Liu, Mei-Hua

    2014-07-01

    A high-resolution micro-grating displacement sensor with diffraction-based and integrated electrostatic actuation is proposed and experimentally demonstrated. The Al reflecting membrane is fabricated at the bottom of a silicon moving part and the Au micro-gratings are patterned on a transparent substrate. This structure forms a phase sensitive diffraction grating, providing the displacement sensitivity of the micro-grating interferometer. It shows sensitivity adjustment and self-calibration capabilities with electrostatic actuation. Additional system components include a coherent light source, photodiodes, and required electronics. Experimental results show that the displacement sensor has a sensitivity of about 1.8 mV/nm and a resolution of less than 1 nm in the linear region. This displacement sensor is very promising in the fields requiring high sensitivity, broad dynamic range, and immunity to electromagnetic interference.

  1. Variance and Covariance of Accumulated Displacement Estimates

    PubMed Central

    Bayer, Matthew; Hall, Timothy J.

    2013-01-01

    Tracking large deformations in tissue using ultrasound can enable the reconstruction of nonlinear elastic parameters, but poses a challenge to displacement estimation algorithms. Such large deformations have to be broken up into steps, each of which contributes an estimation error to the final accumulated displacement map. The work reported here measured the error variance for single-step and accumulated displacement estimates using one-dimensional numerical simulations of ultrasound echo signals, subjected to tissue strain and electronic noise. The covariance between accumulation steps was also computed. These simulations show that errors due to electronic noise are negatively correlated between steps, and therefore accumulate slowly, while errors due to tissue deformation are positively correlated and accumulate quickly. For reasonably low electronic noise levels, the error variance in the accumulated displacement estimates is remarkably constant as a function of step size, but increases with the length of the tracking kernel. PMID:23493610

  2. Air Emissions and Oil Displacement Benefits

    E-print Network

    Michalek, Jeremy J.

    may (1) produce fewer greenhouse gas emissions when powered by electricity instead of gasoline gasoline prices, low- emissAir Emissions and Oil Displacement Benefits from Plug-in Vehicles The electrification of passenger

  3. Arthroscopic treatment of femoral nerve paresthesia caused by an acetabular paralabral cyst.

    PubMed

    Kanauchi, Taira; Suganuma, Jun; Mochizuki, Ryuta; Uchikawa, Shinichi

    2014-05-01

    This report describes a rare case of femoral nerve paresthesia caused by an acetabular paralabral cyst of the hip joint. A 68-year-old woman presented with a 6-month history of right hip pain and paresthesia along the anterior thigh and radiating down to the anterior aspect of the knee. Radiography showed osteoarthritis with a narrowed joint space in the right hip joint. Magnetic resonance imaging showed a cyst with low T1- and high T2-weighted signal intensity arising from a labral tear at the anterior aspect of the acetabulum. The cyst was connected to the joint space and displaced the femoral nerve to the anteromedial side. The lesion was diagnosed as an acetabular paralabral cyst causing femoral neuropathy. Because the main symptom was femoral nerve paresthesia and the patient desired a less invasive procedure, arthroscopic labral repair was performed to stop synovial fluid flow to the paralabral cyst that was causing the femoral nerve paresthesia. After surgery, the cyst and femoral nerve paresthesia disappeared. At the 18-month follow-up, the patient had no recurrence. There have been several reports of neurovascular compression caused by the cyst around the hip joint. To the authors' knowledge, only 3 cases of acetabular paralabral cysts causing sciatica have been reported. The current patient appears to represent a rare case of an acetabular paralabral cyst causing femoral nerve paresthesia. The authors suggest that arthroscopic labral repair for an acetabular paralabral cyst causing neuropathy can be an option for patients who desire a less invasive procedure. PMID:24810828

  4. PDT - PARTICLE DISPLACEMENT TRACKING SOFTWARE

    NASA Technical Reports Server (NTRS)

    Wernet, M. P.

    1994-01-01

    Particle Imaging Velocimetry (PIV) is a quantitative velocity measurement technique for measuring instantaneous planar cross sections of a flow field. The technique offers very high precision (1%) directionally resolved velocity vector estimates, but its use has been limited by high equipment costs and complexity of operation. Particle Displacement Tracking (PDT) is an all-electronic PIV data acquisition and reduction procedure which is simple, fast, and easily implemented. The procedure uses a low power, continuous wave laser and a Charged Coupled Device (CCD) camera to electronically record the particle images. A frame grabber board in a PC is used for data acquisition and reduction processing. PDT eliminates the need for photographic processing, system costs are moderately low, and reduced data are available within seconds of acquisition. The technique results in velocity estimate accuracies on the order of 5%. The software is fully menu-driven from the acquisition to the reduction and analysis of the data. Options are available to acquire a single image or 5- or 25-field series of images separated in time by multiples of 1/60 second. The user may process each image, specifying its boundaries to remove unwanted glare from the periphery and adjusting its background level to clearly resolve the particle images. Data reduction routines determine the particle image centroids and create time history files. PDT then identifies the velocity vectors which describe the particle movement in the flow field. Graphical data analysis routines are included which allow the user to graph the time history files and display the velocity vector maps, interpolated velocity vector grids, iso-velocity vector contours, and flow streamlines. The PDT data processing software is written in FORTRAN 77 and the data acquisition routine is written in C-Language for 80386-based IBM PC compatibles running MS-DOS v3.0 or higher. Machine requirements include 4 MB RAM (3 MB Extended), a single or multiple frequency RGB monitor (EGA or better), a math co-processor, and a pointing device. The printers supported by the graphical analysis routines are the HP Laserjet+, Series II, and Series III with at least 1.5 MB memory. The data acquisition routines require the EPIX 4-MEG video board and optional 12.5MHz oscillator, and associated EPIX software. Data can be acquired from any CCD or RS-170 compatible video camera with pixel resolution of 600hX400v or better. PDT is distributed on one 5.25 inch 360K MS-DOS format diskette. Due to the use of required proprietary software, executable code is not provided on the distribution media. Compiling the source code requires the Microsoft C v5.1 compiler, Microsoft QuickC v2.0, the Microsoft Mouse Library, EPIX Image Processing Libraries, the Microway NDP-Fortran-386 v2.1 compiler, and the Media Cybernetics HALO Professional Graphics Kernal System. Due to the complexities of the machine requirements, COSMIC strongly recommends the purchase and review of the documentation prior to the purchase of the program. The source code, and sample input and output files are provided in PKZIP format; the PKUNZIP utility is included. PDT was developed in 1990. All trade names used are the property of their respective corporate owners.

  5. Theory of multicomponent gas\\/oil displacements

    Microsoft Academic Search

    Franklin M. Orr; Birol Dindoruk; Russell T. Johns

    1995-01-01

    Chromatographic separations that occur during two-phase flow in a porous medium are analyzed for one-dimensional, dispersion-free displacement of a liquid hydrocarbon mixture (oil) by a vapor phase mixture (gas). The authors show that displacement behavior is controlled by a set of key equilibrium the lines, all of which are determined by geometric constructions in composition space: two of the key

  6. 40 CFR 86.419-78 - Engine displacement, motorcycle classes.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Engine displacement, motorcycle classes. 86.419-78...Provisions § 86.419-78 Engine displacement, motorcycle classes. (a)(1) Engine displacement shall be calculated using...

  7. 24 CFR 882.810 - Displacement, relocation, and acquisition.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Displacement, relocation, and acquisition...Homeless Individuals § 882.810 Displacement, relocation, and acquisition. (a) Minimizing displacement. (1) Consistent with the...

  8. 40 CFR 86.419-2006 - Engine displacement, motorcycle classes.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false Engine displacement, motorcycle classes. 86.419-2006...Provisions § 86.419-2006 Engine displacement, motorcycle classes. (a)(1) Engine displacement shall be calculated using...

  9. 24 CFR 583.310 - Displacement, relocation, and acquisition.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Displacement, relocation, and acquisition...Program Requirements § 583.310 Displacement, relocation, and acquisition. (a) Minimizing displacement. Consistent with the other...

  10. 20 CFR 218.30 - Separation, displacement or dismissal allowance.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 false Separation, displacement or dismissal allowance. 218.30...Beginning Date § 218.30 Separation, displacement or dismissal allowance. (a) General...an employee receives a separation, displacement or dismissal allowance from...

  11. 7 CFR 1944.667 - Relocation and displacement.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2009-01-01 true Relocation and displacement. 1944.667 Section 1944.667...Grants § 1944.667 Relocation and displacement. (a) Relocation. ...costs proposed to be allowed. (b) Displacement. The applicant shall include...

  12. 24 CFR 886.138 - Displacement, relocation, and acquisition.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Displacement, relocation, and acquisition...HUD-Held Mortgages § 886.138 Displacement, relocation, and acquisition. (a) Minimizing displacement. Consistent with the other...

  13. 10 CFR 590.209 - Exchanges by displacement.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2010-01-01 false Exchanges by displacement. 590.209 Section 590.209...Gas § 590.209 Exchanges by displacement. Any importer of natural gas may enter into an exchange by displacement agreement without the...

  14. 40 CFR 86.419-78 - Engine displacement, motorcycle classes.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false Engine displacement, motorcycle classes. 86.419-78...Provisions § 86.419-78 Engine displacement, motorcycle classes. (a)(1) Engine displacement shall be calculated using...

  15. 24 CFR 92.353 - Displacement, relocation, and acquisition.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Displacement, relocation, and acquisition...Federal Requirements § 92.353 Displacement, relocation, and acquisition. (a) Minimizing displacement. Consistent with the other...

  16. 24 CFR 583.310 - Displacement, relocation, and acquisition.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2010-04-01 true Displacement, relocation, and acquisition...Program Requirements § 583.310 Displacement, relocation, and acquisition. (a) Minimizing displacement. Consistent with the other...

  17. 40 CFR 86.419-2006 - Engine displacement, motorcycle classes.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Engine displacement, motorcycle classes. 86.419-2006...Provisions § 86.419-2006 Engine displacement, motorcycle classes. (a)(1) Engine displacement shall be calculated using...

  18. 7 CFR 1944.667 - Relocation and displacement.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2009-01-01 true Relocation and displacement. 1944.667 Section 1944.667...Grants § 1944.667 Relocation and displacement. (a) Relocation. ...costs proposed to be allowed. (b) Displacement. The applicant shall include...

  19. 10 CFR 590.209 - Exchanges by displacement.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 false Exchanges by displacement. 590.209 Section 590.209...Gas § 590.209 Exchanges by displacement. Any importer of natural gas may enter into an exchange by displacement agreement without the...

  20. 24 CFR 236.1001 - Displacement, relocation, and acquisition.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Displacement, relocation, and acquisition...Relocation Assistance § 236.1001 Displacement, relocation, and acquisition. (a) Minimizing displacement. Consistent with the other...